diff --git a/data/language/en-GB.txt b/data/language/en-GB.txt
index 352df35239..78c58ea18a 100644
--- a/data/language/en-GB.txt
+++ b/data/language/en-GB.txt
@@ -2258,7 +2258,7 @@ STR_3208    :Track Designs Manager
 STR_3209    :Back to Previous Step:
 STR_3210    :Forward to Next Step:
 STR_3211    :Map size:
-STR_3212    :{POP16}{COMMA16} × {PUSH16}{COMMA16}
+STR_3212    :{COMMA16} × {COMMA16}
 STR_3213    :Can’t decrease map size any further
 STR_3214    :Can’t increase map size any further
 STR_3215    :Too close to edge of map
diff --git a/src/openrct2-ui/input/MouseInput.cpp b/src/openrct2-ui/input/MouseInput.cpp
index f59d2b69d7..e71e1def99 100644
--- a/src/openrct2-ui/input/MouseInput.cpp
+++ b/src/openrct2-ui/input/MouseInput.cpp
@@ -1619,11 +1619,12 @@ void InputScrollViewport(const ScreenCoordsXY& scrollScreenCoords)
         }
 
         // Clamp to the map maximum value (scenario specific)
-        if (mapCoord.x > GetMapSizeMinus2() || mapCoord.y > GetMapSizeMinus2())
+        auto mapSizeMinus2 = GetMapSizeMinus2();
+        if (mapCoord.x > mapSizeMinus2.x || mapCoord.y > mapSizeMinus2.y)
         {
             at_map_edge = 1;
         }
-        if (mapCoord_dy.x > GetMapSizeMinus2() || mapCoord_dy.y > GetMapSizeMinus2())
+        if (mapCoord_dy.x > mapSizeMinus2.x || mapCoord_dy.y > mapSizeMinus2.y)
         {
             at_map_edge_dy = 1;
         }
diff --git a/src/openrct2-ui/windows/Map.cpp b/src/openrct2-ui/windows/Map.cpp
index afe22dd403..03f9ffd15e 100644
--- a/src/openrct2-ui/windows/Map.cpp
+++ b/src/openrct2-ui/windows/Map.cpp
@@ -653,7 +653,7 @@ static void WindowMapTextinput(rct_window* w, rct_widgetindex widgetIndex, char*
                 size += 2;
                 size = std::clamp(size, MINIMUM_MAP_SIZE_TECHNICAL, MAXIMUM_MAP_SIZE_TECHNICAL);
 
-                auto changeMapSizeAction = ChangeMapSizeAction(size);
+                auto changeMapSizeAction = ChangeMapSizeAction({ size, size });
                 GameActions::Execute(&changeMapSizeAction);
                 w->Invalidate();
             }
@@ -968,8 +968,8 @@ static void WindowMapShowDefaultScenarioEditorButtons(rct_window* w)
         w->widgets[WIDX_MAP_GENERATOR].type = WindowWidgetType::Button;
 
     auto ft = Formatter::Common();
-    ft.Increment(2);
-    ft.Add<uint16_t>(gMapSize - 2);
+    ft.Add<uint16_t>(gMapSize.x - 2);
+    ft.Add<uint16_t>(gMapSize.y - 2);
 }
 
 static void WindowMapInputsizeLand(rct_window* w)
@@ -1359,7 +1359,7 @@ static void WindowMapSetPeepSpawnToolDown(const ScreenCoordsXY& screenCoords)
  */
 static void MapWindowIncreaseMapSize()
 {
-    auto increaseMapSizeAction = ChangeMapSizeAction(gMapSize + 1);
+    auto increaseMapSizeAction = ChangeMapSizeAction({ gMapSize.x + 1, gMapSize.y + 1 });
     GameActions::Execute(&increaseMapSizeAction);
 }
 
@@ -1369,7 +1369,7 @@ static void MapWindowIncreaseMapSize()
  */
 static void MapWindowDecreaseMapSize()
 {
-    auto decreaseMapSizeAction = ChangeMapSizeAction(gMapSize - 1);
+    auto decreaseMapSizeAction = ChangeMapSizeAction({ gMapSize.x - 1, gMapSize.y - 1 });
     GameActions::Execute(&decreaseMapSizeAction);
 }
 
diff --git a/src/openrct2-ui/windows/RideConstruction.cpp b/src/openrct2-ui/windows/RideConstruction.cpp
index 009e072232..146c4d1248 100644
--- a/src/openrct2-ui/windows/RideConstruction.cpp
+++ b/src/openrct2-ui/windows/RideConstruction.cpp
@@ -2129,9 +2129,9 @@ static void Sub6CbcE2(
     if (ride == nullptr)
         return;
 
-    int32_t preserveMapSize = gMapSize;
+    auto preserveMapSize = gMapSize;
 
-    gMapSize = MAXIMUM_MAP_SIZE_TECHNICAL;
+    gMapSize = { MAXIMUM_MAP_SIZE_TECHNICAL, MAXIMUM_MAP_SIZE_TECHNICAL };
 
     const auto& ted = GetTrackElementDescriptor(trackType);
     const auto* trackBlock = ted.Block;
diff --git a/src/openrct2/Context.cpp b/src/openrct2/Context.cpp
index bc6ca29b0a..28a36c1ec9 100644
--- a/src/openrct2/Context.cpp
+++ b/src/openrct2/Context.cpp
@@ -502,7 +502,7 @@ namespace OpenRCT2
             viewport_init_all();
 
             _gameState = std::make_unique<GameState>();
-            _gameState->InitAll(150);
+            _gameState->InitAll({ 150, 150 });
 
             _titleScreen = std::make_unique<TitleScreen>(*_gameState);
             _uiContext->Initialise();
diff --git a/src/openrct2/Editor.cpp b/src/openrct2/Editor.cpp
index cc06472969..31bf94c957 100644
--- a/src/openrct2/Editor.cpp
+++ b/src/openrct2/Editor.cpp
@@ -94,7 +94,7 @@ namespace Editor
     {
         OpenRCT2::Audio::StopAll();
         object_list_load();
-        OpenRCT2::GetContext()->GetGameState()->InitAll(150);
+        OpenRCT2::GetContext()->GetGameState()->InitAll({ 150, 150 });
         gScreenFlags = SCREEN_FLAGS_SCENARIO_EDITOR;
         gEditorStep = EditorStep::ObjectSelection;
         gParkFlags |= PARK_FLAGS_SHOW_REAL_GUEST_NAMES;
@@ -170,7 +170,7 @@ namespace Editor
 
         object_manager_unload_all_objects();
         object_list_load();
-        OpenRCT2::GetContext()->GetGameState()->InitAll(150);
+        OpenRCT2::GetContext()->GetGameState()->InitAll({ 150, 150 });
         SetAllLandOwned();
         gEditorStep = EditorStep::ObjectSelection;
         viewport_init_all();
@@ -191,7 +191,7 @@ namespace Editor
 
         object_manager_unload_all_objects();
         object_list_load();
-        OpenRCT2::GetContext()->GetGameState()->InitAll(150);
+        OpenRCT2::GetContext()->GetGameState()->InitAll({ 150, 150 });
         SetAllLandOwned();
         gEditorStep = EditorStep::ObjectSelection;
         viewport_init_all();
@@ -206,9 +206,7 @@ namespace Editor
      */
     static void SetAllLandOwned()
     {
-        int32_t mapSize = gMapSize;
-
-        MapRange range = { 64, 64, (mapSize - 3) * 32, (mapSize - 3) * 32 };
+        MapRange range = { 64, 64, (gMapSize.x - 3) * 32, (gMapSize.y - 3) * 32 };
         auto landSetRightsAction = LandSetRightsAction(range, LandSetRightSetting::SetForSale);
         landSetRightsAction.SetFlags(GAME_COMMAND_FLAG_NO_SPEND);
         GameActions::Execute(&landSetRightsAction);
diff --git a/src/openrct2/Game.cpp b/src/openrct2/Game.cpp
index ff479d8432..bd6d81532d 100644
--- a/src/openrct2/Game.cpp
+++ b/src/openrct2/Game.cpp
@@ -424,7 +424,7 @@ void game_fix_save_vars()
 
             // Fix the invisible border tiles.
             // At this point, we can be sure that surfaceElement is not NULL.
-            if (x == 0 || x == gMapSize - 1 || y == 0 || y == gMapSize - 1)
+            if (x == 0 || x == gMapSize.x - 1 || y == 0 || y == gMapSize.y - 1)
             {
                 surfaceElement->SetBaseZ(MINIMUM_LAND_HEIGHT_BIG);
                 surfaceElement->SetClearanceZ(MINIMUM_LAND_HEIGHT_BIG);
diff --git a/src/openrct2/GameState.cpp b/src/openrct2/GameState.cpp
index 71d4dc3ab2..6845573bd3 100644
--- a/src/openrct2/GameState.cpp
+++ b/src/openrct2/GameState.cpp
@@ -54,7 +54,7 @@ GameState::GameState()
 /**
  * Initialises the map, park etc. basically all S6 data.
  */
-void GameState::InitAll(int32_t mapSize)
+void GameState::InitAll(const TileCoordsXY& mapSize)
 {
     PROFILED_FUNCTION();
 
diff --git a/src/openrct2/GameState.h b/src/openrct2/GameState.h
index 5768543c96..2e203aad0b 100644
--- a/src/openrct2/GameState.h
+++ b/src/openrct2/GameState.h
@@ -10,6 +10,7 @@
 #pragma once
 
 #include "Date.h"
+#include "world/Location.hpp"
 
 #include <array>
 #include <chrono>
@@ -82,7 +83,7 @@ namespace OpenRCT2
             return *_park;
         }
 
-        void InitAll(int32_t mapSize);
+        void InitAll(const TileCoordsXY& mapSize);
         void Tick();
         void UpdateLogic(LogicTimings* timings = nullptr);
 
diff --git a/src/openrct2/actions/ChangeMapSizeAction.cpp b/src/openrct2/actions/ChangeMapSizeAction.cpp
index 33975206f2..44b490e21e 100644
--- a/src/openrct2/actions/ChangeMapSizeAction.cpp
+++ b/src/openrct2/actions/ChangeMapSizeAction.cpp
@@ -15,7 +15,7 @@
 #include "../ui/WindowManager.h"
 #include "../windows/Intent.h"
 
-ChangeMapSizeAction::ChangeMapSizeAction(const int32_t targetSize)
+ChangeMapSizeAction::ChangeMapSizeAction(const TileCoordsXY targetSize)
     : _targetSize(targetSize)
 {
 }
@@ -33,11 +33,11 @@ void ChangeMapSizeAction::Serialise(DataSerialiser& stream)
 
 GameActions::Result ChangeMapSizeAction::Query() const
 {
-    if (_targetSize > MAXIMUM_MAP_SIZE_TECHNICAL)
+    if (_targetSize.x > MAXIMUM_MAP_SIZE_TECHNICAL || _targetSize.y > MAXIMUM_MAP_SIZE_TECHNICAL)
     {
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_INCREASE_MAP_SIZE_ANY_FURTHER, STR_NONE);
     }
-    if (_targetSize < 16)
+    if (_targetSize.x < 16 || _targetSize.y < 16)
     {
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_DECREASE_MAP_SIZE_ANY_FURTHER, STR_NONE);
     }
@@ -46,18 +46,23 @@ GameActions::Result ChangeMapSizeAction::Query() const
 
 GameActions::Result ChangeMapSizeAction::Execute() const
 {
-    while (gMapSize != _targetSize)
+    // Expand map
+    while (_targetSize.x > gMapSize.x)
     {
-        if (_targetSize < gMapSize)
-        {
-            gMapSize--;
-            map_remove_out_of_range_elements();
-        }
-        else
-        {
-            gMapSize++;
-            map_extend_boundary_surface();
-        }
+        gMapSize.x++;
+        map_extend_boundary_surface_x();
+    }
+    while (_targetSize.y > gMapSize.y)
+    {
+        gMapSize.y++;
+        map_extend_boundary_surface_y();
+    }
+
+    // Shrink map
+    if (_targetSize.x < gMapSize.x || _targetSize.y < gMapSize.y)
+    {
+        gMapSize = _targetSize;
+        map_remove_out_of_range_elements();
     }
 
     auto* ctx = OpenRCT2::GetContext();
@@ -71,5 +76,6 @@ GameActions::Result ChangeMapSizeAction::Execute() const
 
 void ChangeMapSizeAction::AcceptParameters(GameActionParameterVisitor& visitor)
 {
-    visitor.Visit("targetSize", _targetSize);
+    visitor.Visit("targetSizeX", _targetSize.x);
+    visitor.Visit("targetSizeY", _targetSize.y);
 }
diff --git a/src/openrct2/actions/ChangeMapSizeAction.h b/src/openrct2/actions/ChangeMapSizeAction.h
index 650a57208c..332dd4cec6 100644
--- a/src/openrct2/actions/ChangeMapSizeAction.h
+++ b/src/openrct2/actions/ChangeMapSizeAction.h
@@ -16,7 +16,7 @@ class ChangeMapSizeAction final : public GameActionBase<GameCommand::ChangeMapSi
 {
 public:
     ChangeMapSizeAction() = default;
-    ChangeMapSizeAction(const int32_t targetSize);
+    ChangeMapSizeAction(const TileCoordsXY targetSize);
 
     void AcceptParameters(GameActionParameterVisitor& visitor) override;
     uint16_t GetActionFlags() const override;
@@ -26,5 +26,5 @@ public:
     GameActions::Result Execute() const override;
 
 private:
-    int32_t _targetSize;
+    TileCoordsXY _targetSize;
 };
diff --git a/src/openrct2/actions/ClearAction.cpp b/src/openrct2/actions/ClearAction.cpp
index 9ae25bafbd..d8fd49167b 100644
--- a/src/openrct2/actions/ClearAction.cpp
+++ b/src/openrct2/actions/ClearAction.cpp
@@ -70,14 +70,10 @@ GameActions::Result ClearAction::QueryExecute(bool executing) const
     rct_string_id errorMessage = STR_NONE;
     money32 totalCost = 0;
 
-    auto x0 = std::max(_range.GetLeft(), 32);
-    auto y0 = std::max(_range.GetTop(), 32);
-    auto x1 = std::min(_range.GetRight(), GetMapSizeMaxXY());
-    auto y1 = std::min(_range.GetBottom(), GetMapSizeMaxXY());
-
-    for (int32_t y = y0; y <= y1; y += COORDS_XY_STEP)
+    auto validRange = ClampRangeWithinMap(_range);
+    for (int32_t y = validRange.GetTop(); y <= validRange.GetBottom(); y += COORDS_XY_STEP)
     {
-        for (int32_t x = x0; x <= x1; x += COORDS_XY_STEP)
+        for (int32_t x = validRange.GetLeft(); x <= validRange.GetRight(); x += COORDS_XY_STEP)
         {
             if (LocationValid({ x, y }) && MapCanClearAt({ x, y }))
             {
diff --git a/src/openrct2/actions/FootpathPlaceAction.cpp b/src/openrct2/actions/FootpathPlaceAction.cpp
index 93ee989e19..ba1aefbbed 100644
--- a/src/openrct2/actions/FootpathPlaceAction.cpp
+++ b/src/openrct2/actions/FootpathPlaceAction.cpp
@@ -456,14 +456,15 @@ GameActions::Result FootpathPlaceAction::ElementInsertExecute(GameActions::Resul
  */
 void FootpathPlaceAction::AutomaticallySetPeepSpawn() const
 {
+    auto mapSizeUnits = GetMapSizeUnits();
     uint8_t direction = 0;
     if (_loc.x != 32)
     {
         direction++;
-        if (_loc.y != GetMapSizeUnits() - 32)
+        if (_loc.y != mapSizeUnits.y - 32)
         {
             direction++;
-            if (_loc.x != GetMapSizeUnits() - 32)
+            if (_loc.x != mapSizeUnits.x - 32)
             {
                 direction++;
                 if (_loc.y != 32)
diff --git a/src/openrct2/actions/LandBuyRightsAction.cpp b/src/openrct2/actions/LandBuyRightsAction.cpp
index 2fa1c32d71..6a1bd4fd08 100644
--- a/src/openrct2/actions/LandBuyRightsAction.cpp
+++ b/src/openrct2/actions/LandBuyRightsAction.cpp
@@ -64,10 +64,11 @@ GameActions::Result LandBuyRightsAction::QueryExecute(bool isExecuting) const
 
     MapRange normRange = _range.Normalise();
     // Keep big coordinates within map boundaries
+    auto mapSizeMaxXY = GetMapSizeMaxXY();
     auto aX = std::max<decltype(normRange.GetLeft())>(32, normRange.GetLeft());
-    auto bX = std::min<decltype(normRange.GetRight())>(GetMapSizeMaxXY(), normRange.GetRight());
+    auto bX = std::min<decltype(normRange.GetRight())>(mapSizeMaxXY.x, normRange.GetRight());
     auto aY = std::max<decltype(normRange.GetTop())>(32, normRange.GetTop());
-    auto bY = std::min<decltype(normRange.GetBottom())>(GetMapSizeMaxXY(), normRange.GetBottom());
+    auto bY = std::min<decltype(normRange.GetBottom())>(mapSizeMaxXY.y, normRange.GetBottom());
 
     MapRange validRange = MapRange{ aX, aY, bX, bY };
 
diff --git a/src/openrct2/actions/LandLowerAction.cpp b/src/openrct2/actions/LandLowerAction.cpp
index 702697fa38..1e87b34b92 100644
--- a/src/openrct2/actions/LandLowerAction.cpp
+++ b/src/openrct2/actions/LandLowerAction.cpp
@@ -62,13 +62,7 @@ GameActions::Result LandLowerAction::QueryExecute(bool isExecuting) const
     if (_selectionType >= MAP_SELECT_TYPE_EDGE_0 && _selectionType <= MAP_SELECT_TYPE_EDGE_3)
         tableRow -= MAP_SELECT_TYPE_EDGE_0 - MAP_SELECT_TYPE_FULL - 1;
 
-    // Keep big coordinates within map boundaries
-    auto aX = std::max<decltype(_range.GetLeft())>(32, _range.GetLeft());
-    auto bX = std::min<decltype(_range.GetRight())>(GetMapSizeMaxXY(), _range.GetRight());
-    auto aY = std::max<decltype(_range.GetTop())>(32, _range.GetTop());
-    auto bY = std::min<decltype(_range.GetBottom())>(GetMapSizeMaxXY(), _range.GetBottom());
-
-    MapRange validRange = MapRange{ aX, aY, bX, bY };
+    auto validRange = ClampRangeWithinMap(_range);
 
     res.Position = { _coords.x, _coords.y, tile_element_height(_coords) };
     res.Expenditure = ExpenditureType::Landscaping;
diff --git a/src/openrct2/actions/LandRaiseAction.cpp b/src/openrct2/actions/LandRaiseAction.cpp
index e9585e0d7b..e2cc4666fb 100644
--- a/src/openrct2/actions/LandRaiseAction.cpp
+++ b/src/openrct2/actions/LandRaiseAction.cpp
@@ -63,13 +63,7 @@ GameActions::Result LandRaiseAction::QueryExecute(bool isExecuting) const
     if (_selectionType >= MAP_SELECT_TYPE_EDGE_0 && _selectionType <= MAP_SELECT_TYPE_EDGE_3)
         tableRow -= MAP_SELECT_TYPE_EDGE_0 - MAP_SELECT_TYPE_FULL - 1;
 
-    // Keep big coordinates within map boundaries
-    auto aX = std::max<decltype(_range.GetLeft())>(32, _range.GetLeft());
-    auto bX = std::min<decltype(_range.GetRight())>(GetMapSizeMaxXY(), _range.GetRight());
-    auto aY = std::max<decltype(_range.GetTop())>(32, _range.GetTop());
-    auto bY = std::min<decltype(_range.GetBottom())>(GetMapSizeMaxXY(), _range.GetBottom());
-
-    MapRange validRange = MapRange{ aX, aY, bX, bY };
+    auto validRange = ClampRangeWithinMap(_range);
 
     res.Position = { _coords.x, _coords.y, tile_element_height(_coords) };
     res.Expenditure = ExpenditureType::Landscaping;
diff --git a/src/openrct2/actions/LandSetHeightAction.cpp b/src/openrct2/actions/LandSetHeightAction.cpp
index ddaabf6243..c2fdcefcbc 100644
--- a/src/openrct2/actions/LandSetHeightAction.cpp
+++ b/src/openrct2/actions/LandSetHeightAction.cpp
@@ -183,7 +183,8 @@ rct_string_id LandSetHeightAction::CheckParameters() const
         return STR_OFF_EDGE_OF_MAP;
     }
 
-    if (_coords.x > GetMapSizeMaxXY() || _coords.y > GetMapSizeMaxXY())
+    auto mapSizeMax = GetMapSizeMaxXY();
+    if (_coords.x > mapSizeMax.x || _coords.y > mapSizeMax.y)
     {
         return STR_OFF_EDGE_OF_MAP;
     }
diff --git a/src/openrct2/actions/LandSetRightsAction.cpp b/src/openrct2/actions/LandSetRightsAction.cpp
index 8dac23eaf2..5393d1ca08 100644
--- a/src/openrct2/actions/LandSetRightsAction.cpp
+++ b/src/openrct2/actions/LandSetRightsAction.cpp
@@ -67,15 +67,7 @@ GameActions::Result LandSetRightsAction::QueryExecute(bool isExecuting) const
 {
     auto res = GameActions::Result();
 
-    MapRange normRange = _range.Normalise();
-    // Keep big coordinates within map boundaries
-    auto aX = std::max<decltype(normRange.GetLeft())>(32, normRange.GetLeft());
-    auto bX = std::min<decltype(normRange.GetRight())>(GetMapSizeMaxXY(), normRange.GetRight());
-    auto aY = std::max<decltype(normRange.GetTop())>(32, normRange.GetTop());
-    auto bY = std::min<decltype(normRange.GetBottom())>(GetMapSizeMaxXY(), normRange.GetBottom());
-
-    MapRange validRange = MapRange{ aX, aY, bX, bY };
-
+    auto validRange = ClampRangeWithinMap(_range.Normalise());
     CoordsXYZ centre{ (validRange.GetLeft() + validRange.GetRight()) / 2 + 16,
                       (validRange.GetTop() + validRange.GetBottom()) / 2 + 16, 0 };
     centre.z = tile_element_height(centre);
diff --git a/src/openrct2/actions/LargeScenerySetColourAction.cpp b/src/openrct2/actions/LargeScenerySetColourAction.cpp
index 0848051f1d..255c20af7d 100644
--- a/src/openrct2/actions/LargeScenerySetColourAction.cpp
+++ b/src/openrct2/actions/LargeScenerySetColourAction.cpp
@@ -53,7 +53,8 @@ GameActions::Result LargeScenerySetColourAction::QueryExecute(bool isExecuting)
     res.Position.z = tile_element_height(_loc);
     res.ErrorTitle = STR_CANT_REPAINT_THIS;
 
-    if (_loc.x < 0 || _loc.y < 0 || _loc.x > GetMapSizeMaxXY() || _loc.y > GetMapSizeMaxXY())
+    auto mapSizeMax = GetMapSizeMaxXY();
+    if (_loc.x < 0 || _loc.y < 0 || _loc.x > mapSizeMax.x || _loc.y > mapSizeMax.y)
     {
         log_error("Invalid x / y coordinates: x = %d, y = %d", _loc.x, _loc.y);
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_REPAINT_THIS, STR_NONE);
diff --git a/src/openrct2/actions/PlaceParkEntranceAction.cpp b/src/openrct2/actions/PlaceParkEntranceAction.cpp
index 8f7823772d..8fb7704430 100644
--- a/src/openrct2/actions/PlaceParkEntranceAction.cpp
+++ b/src/openrct2/actions/PlaceParkEntranceAction.cpp
@@ -51,8 +51,8 @@ GameActions::Result PlaceParkEntranceAction::Query() const
     res.Expenditure = ExpenditureType::LandPurchase;
     res.Position = { _loc.x, _loc.y, _loc.z };
 
-    if (!LocationValid(_loc) || _loc.x <= 32 || _loc.y <= 32 || _loc.x >= (GetMapSizeUnits() - 32)
-        || _loc.y >= (GetMapSizeUnits() - 32))
+    auto mapSizeUnits = GetMapSizeUnits() - CoordsXY{ 32, 32 };
+    if (!LocationValid(_loc) || _loc.x <= 32 || _loc.y <= 32 || _loc.x >= mapSizeUnits.x || _loc.y >= mapSizeUnits.y)
     {
         return GameActions::Result(
             GameActions::Status::InvalidParameters, STR_CANT_BUILD_THIS_HERE, STR_TOO_CLOSE_TO_EDGE_OF_MAP);
diff --git a/src/openrct2/actions/PlacePeepSpawnAction.cpp b/src/openrct2/actions/PlacePeepSpawnAction.cpp
index 140967d7b7..471116395b 100644
--- a/src/openrct2/actions/PlacePeepSpawnAction.cpp
+++ b/src/openrct2/actions/PlacePeepSpawnAction.cpp
@@ -46,8 +46,9 @@ GameActions::Result PlacePeepSpawnAction::Query() const
     res.Expenditure = ExpenditureType::LandPurchase;
     res.Position = _location;
 
-    if (!LocationValid(_location) || _location.x <= 16 || _location.y <= 16 || _location.x >= (GetMapSizeUnits() - 16)
-        || _location.y >= (GetMapSizeUnits() - 16))
+    auto mapSizeUnits = GetMapSizeUnits() - CoordsXY{ 16, 16 };
+    if (!LocationValid(_location) || _location.x <= 16 || _location.y <= 16 || _location.x >= mapSizeUnits.x
+        || _location.y >= mapSizeUnits.y)
     {
         return GameActions::Result(
             GameActions::Status::InvalidParameters, STR_ERR_CANT_PLACE_PEEP_SPAWN_HERE, STR_OFF_EDGE_OF_MAP);
diff --git a/src/openrct2/actions/RideDemolishAction.cpp b/src/openrct2/actions/RideDemolishAction.cpp
index afe6f3186c..c64170a64b 100644
--- a/src/openrct2/actions/RideDemolishAction.cpp
+++ b/src/openrct2/actions/RideDemolishAction.cpp
@@ -195,9 +195,9 @@ money32 RideDemolishAction::DemolishTracks() const
     uint8_t oldpaused = gGamePaused;
     gGamePaused = 0;
 
-    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize; ++tilePos.x)
+    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize.x; ++tilePos.x)
     {
-        for (tilePos.y = 0; tilePos.y < gMapSize; ++tilePos.y)
+        for (tilePos.y = 0; tilePos.y < gMapSize.y; ++tilePos.y)
         {
             const auto tileCoords = tilePos.ToCoordsXY();
             // Keep retrying a tile coordinate until there are no more items to remove
diff --git a/src/openrct2/actions/SetCheatAction.cpp b/src/openrct2/actions/SetCheatAction.cpp
index d61d2ad1c8..d271c4c692 100644
--- a/src/openrct2/actions/SetCheatAction.cpp
+++ b/src/openrct2/actions/SetCheatAction.cpp
@@ -683,12 +683,12 @@ void SetCheatAction::SetStaffSpeed(uint8_t value) const
 
 void SetCheatAction::OwnAllLand() const
 {
-    const int32_t min = 32;
-    const int32_t max = GetMapSizeUnits() - 32;
+    const auto min = CoordsXY{ 32, 32 };
+    const auto max = GetMapSizeUnits() - CoordsXY{ 32, 32 };
 
-    for (CoordsXY coords = { min, min }; coords.y <= max; coords.y += COORDS_XY_STEP)
+    for (CoordsXY coords = min; coords.y <= max.y; coords.y += COORDS_XY_STEP)
     {
-        for (coords.x = min; coords.x <= max; coords.x += COORDS_XY_STEP)
+        for (coords.x = min.x; coords.x <= max.x; coords.x += COORDS_XY_STEP)
         {
             auto* surfaceElement = map_get_surface_element_at(coords);
             if (surfaceElement == nullptr)
diff --git a/src/openrct2/actions/SmallSceneryPlaceAction.cpp b/src/openrct2/actions/SmallSceneryPlaceAction.cpp
index 30ce122e4f..30abcbb6b4 100644
--- a/src/openrct2/actions/SmallSceneryPlaceAction.cpp
+++ b/src/openrct2/actions/SmallSceneryPlaceAction.cpp
@@ -103,7 +103,8 @@ GameActions::Result SmallSceneryPlaceAction::Query() const
             GameActions::Status::NoFreeElements, STR_CANT_POSITION_THIS_HERE, STR_TILE_ELEMENT_LIMIT_REACHED);
     }
 
-    if (!_trackDesignDrawingPreview && (_loc.x > GetMapSizeMaxXY() || _loc.y > GetMapSizeMaxXY()))
+    auto maxSizeMax = GetMapSizeMaxXY();
+    if (!_trackDesignDrawingPreview && (_loc.x > maxSizeMax.x || _loc.y > maxSizeMax.y))
     {
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_POSITION_THIS_HERE, STR_NONE);
     }
diff --git a/src/openrct2/actions/SurfaceSetStyleAction.cpp b/src/openrct2/actions/SurfaceSetStyleAction.cpp
index 0a15ea895f..3656018558 100644
--- a/src/openrct2/actions/SurfaceSetStyleAction.cpp
+++ b/src/openrct2/actions/SurfaceSetStyleAction.cpp
@@ -39,14 +39,7 @@ GameActions::Result SurfaceSetStyleAction::Query() const
     res.ErrorTitle = STR_CANT_CHANGE_LAND_TYPE;
     res.Expenditure = ExpenditureType::Landscaping;
 
-    auto normRange = _range.Normalise();
-    auto x0 = std::max(normRange.GetLeft(), 32);
-    auto y0 = std::max(normRange.GetTop(), 32);
-    auto x1 = std::min(normRange.GetRight(), GetMapSizeMaxXY());
-    auto y1 = std::min(normRange.GetBottom(), GetMapSizeMaxXY());
-
-    MapRange validRange{ x0, y0, x1, y1 };
-
+    auto validRange = ClampRangeWithinMap(_range.Normalise());
     auto& objManager = OpenRCT2::GetContext()->GetObjectManager();
     if (_surfaceStyle != OBJECT_ENTRY_INDEX_NULL)
     {
@@ -158,14 +151,7 @@ GameActions::Result SurfaceSetStyleAction::Execute() const
     res.ErrorTitle = STR_CANT_CHANGE_LAND_TYPE;
     res.Expenditure = ExpenditureType::Landscaping;
 
-    auto normRange = _range.Normalise();
-    auto x0 = std::max(normRange.GetLeft(), 32);
-    auto y0 = std::max(normRange.GetTop(), 32);
-    auto x1 = std::min(normRange.GetRight(), GetMapSizeMaxXY());
-    auto y1 = std::min(normRange.GetBottom(), GetMapSizeMaxXY());
-
-    MapRange validRange{ x0, y0, x1, y1 };
-
+    auto validRange = ClampRangeWithinMap(_range.Normalise());
     auto xMid = (validRange.GetLeft() + validRange.GetRight()) / 2 + 16;
     auto yMid = (validRange.GetTop() + validRange.GetBottom()) / 2 + 16;
     auto heightMid = tile_element_height({ xMid, yMid });
diff --git a/src/openrct2/actions/WallPlaceAction.cpp b/src/openrct2/actions/WallPlaceAction.cpp
index 4ca0298dbd..8987ee24ac 100644
--- a/src/openrct2/actions/WallPlaceAction.cpp
+++ b/src/openrct2/actions/WallPlaceAction.cpp
@@ -78,6 +78,7 @@ GameActions::Result WallPlaceAction::Query() const
         return GameActions::Result(GameActions::Status::NotOwned, STR_CANT_BUILD_THIS_HERE, STR_NONE);
     }
 
+    auto mapSizeMax = GetMapSizeMaxXY();
     if (!(gScreenFlags & SCREEN_FLAGS_SCENARIO_EDITOR) && !(GetFlags() & GAME_COMMAND_FLAG_PATH_SCENERY) && !gCheatsSandboxMode)
     {
         if (_loc.z == 0)
@@ -92,7 +93,7 @@ GameActions::Result WallPlaceAction::Query() const
             return GameActions::Result(GameActions::Status::NotOwned, STR_CANT_BUILD_THIS_HERE, STR_LAND_NOT_OWNED_BY_PARK);
         }
     }
-    else if (!_trackDesignDrawingPreview && (_loc.x > GetMapSizeMaxXY() || _loc.y > GetMapSizeMaxXY()))
+    else if (!_trackDesignDrawingPreview && (_loc.x > mapSizeMax.x || _loc.y > mapSizeMax.y))
     {
         log_error("Invalid x/y coordinates. x = %d y = %d", _loc.x, _loc.y);
         return GameActions::Result(GameActions::Status::InvalidParameters, STR_CANT_BUILD_THIS_HERE, STR_NONE);
diff --git a/src/openrct2/actions/WaterLowerAction.cpp b/src/openrct2/actions/WaterLowerAction.cpp
index c6f1e2e82d..c3839bb2fe 100644
--- a/src/openrct2/actions/WaterLowerAction.cpp
+++ b/src/openrct2/actions/WaterLowerAction.cpp
@@ -45,14 +45,7 @@ GameActions::Result WaterLowerAction::QueryExecute(bool isExecuting) const
 {
     auto res = GameActions::Result();
 
-    // Keep big coordinates within map boundaries
-    auto aX = std::max<decltype(_range.GetLeft())>(32, _range.GetLeft());
-    auto bX = std::min<decltype(_range.GetRight())>(GetMapSizeMaxXY(), _range.GetRight());
-    auto aY = std::max<decltype(_range.GetTop())>(32, _range.GetTop());
-    auto bY = std::min<decltype(_range.GetBottom())>(GetMapSizeMaxXY(), _range.GetBottom());
-
-    MapRange validRange = MapRange{ aX, aY, bX, bY };
-
+    auto validRange = ClampRangeWithinMap(_range);
     res.Position.x = ((validRange.GetLeft() + validRange.GetRight()) / 2) + 16;
     res.Position.y = ((validRange.GetTop() + validRange.GetBottom()) / 2) + 16;
     int16_t z = tile_element_height(res.Position);
diff --git a/src/openrct2/actions/WaterRaiseAction.cpp b/src/openrct2/actions/WaterRaiseAction.cpp
index 279c395622..ae3b7b0ab7 100644
--- a/src/openrct2/actions/WaterRaiseAction.cpp
+++ b/src/openrct2/actions/WaterRaiseAction.cpp
@@ -45,14 +45,7 @@ GameActions::Result WaterRaiseAction::QueryExecute(bool isExecuting) const
 {
     auto res = GameActions::Result();
 
-    // Keep big coordinates within map boundaries
-    auto aX = std::max<decltype(_range.GetLeft())>(32, _range.GetLeft());
-    auto bX = std::min<decltype(_range.GetRight())>(GetMapSizeMaxXY(), _range.GetRight());
-    auto aY = std::max<decltype(_range.GetTop())>(32, _range.GetTop());
-    auto bY = std::min<decltype(_range.GetBottom())>(GetMapSizeMaxXY(), _range.GetBottom());
-
-    MapRange validRange = MapRange{ aX, aY, bX, bY };
-
+    auto validRange = ClampRangeWithinMap(_range);
     res.Position.x = ((validRange.GetLeft() + validRange.GetRight()) / 2) + 16;
     res.Position.y = ((validRange.GetTop() + validRange.GetBottom()) / 2) + 16;
     int32_t z = tile_element_height(res.Position);
diff --git a/src/openrct2/actions/WaterSetHeightAction.cpp b/src/openrct2/actions/WaterSetHeightAction.cpp
index 3e458a6776..ba00851208 100644
--- a/src/openrct2/actions/WaterSetHeightAction.cpp
+++ b/src/openrct2/actions/WaterSetHeightAction.cpp
@@ -133,7 +133,8 @@ GameActions::Result WaterSetHeightAction::Execute() const
 
 rct_string_id WaterSetHeightAction::CheckParameters() const
 {
-    if (_coords.x > GetMapSizeMaxXY() || _coords.y > GetMapSizeMaxXY())
+    auto mapSizeMax = GetMapSizeMaxXY();
+    if (_coords.x > mapSizeMax.x || _coords.y > mapSizeMax.y)
     {
         return STR_OFF_EDGE_OF_MAP;
     }
diff --git a/src/openrct2/cmdline/BenchSpriteSort.cpp b/src/openrct2/cmdline/BenchSpriteSort.cpp
index 1d193b411d..48d57cb4af 100644
--- a/src/openrct2/cmdline/BenchSpriteSort.cpp
+++ b/src/openrct2/cmdline/BenchSpriteSort.cpp
@@ -87,9 +87,8 @@ static std::vector<RecordedPaintSession> extract_paint_session(std::string_view
         gIntroState = IntroState::None;
         gScreenFlags = SCREEN_FLAGS_PLAYING;
 
-        int32_t mapSize = gMapSize;
-        int32_t resolutionWidth = (mapSize * 32 * 2);
-        int32_t resolutionHeight = (mapSize * 32 * 1);
+        int32_t resolutionWidth = (gMapSize.x * 32 * 2);
+        int32_t resolutionHeight = (gMapSize.y * 32 * 1);
 
         resolutionWidth += 8;
         resolutionHeight += 128;
@@ -103,8 +102,8 @@ static std::vector<RecordedPaintSession> extract_paint_session(std::string_view
         viewport.var_11 = 0;
         viewport.flags = 0;
 
-        int32_t customX = (gMapSize / 2) * 32 + 16;
-        int32_t customY = (gMapSize / 2) * 32 + 16;
+        int32_t customX = (gMapSize.x / 2) * 32 + 16;
+        int32_t customY = (gMapSize.y / 2) * 32 + 16;
 
         int32_t x = 0, y = 0;
         int32_t z = tile_element_height({ customX, customY });
diff --git a/src/openrct2/core/DataSerialiserTraits.h b/src/openrct2/core/DataSerialiserTraits.h
index 41f11c2a06..7916508cc6 100644
--- a/src/openrct2/core/DataSerialiserTraits.h
+++ b/src/openrct2/core/DataSerialiserTraits.h
@@ -484,6 +484,27 @@ template<> struct DataSerializerTraits_t<TileElement>
     }
 };
 
+template<> struct DataSerializerTraits_t<TileCoordsXY>
+{
+    static void encode(OpenRCT2::IStream* stream, const TileCoordsXY& coords)
+    {
+        stream->WriteValue(ByteSwapBE(coords.x));
+        stream->WriteValue(ByteSwapBE(coords.y));
+    }
+    static void decode(OpenRCT2::IStream* stream, TileCoordsXY& coords)
+    {
+        auto x = ByteSwapBE(stream->ReadValue<int32_t>());
+        auto y = ByteSwapBE(stream->ReadValue<int32_t>());
+        coords = TileCoordsXY{ x, y };
+    }
+    static void log(OpenRCT2::IStream* stream, const TileCoordsXY& coords)
+    {
+        char msg[128] = {};
+        snprintf(msg, sizeof(msg), "TileCoordsXY(x = %d, y = %d)", coords.x, coords.y);
+        stream->Write(msg, strlen(msg));
+    }
+};
+
 template<> struct DataSerializerTraits_t<CoordsXY>
 {
     static void encode(OpenRCT2::IStream* stream, const CoordsXY& coords)
diff --git a/src/openrct2/interface/Screenshot.cpp b/src/openrct2/interface/Screenshot.cpp
index 93b02f9fce..a303b05cc0 100644
--- a/src/openrct2/interface/Screenshot.cpp
+++ b/src/openrct2/interface/Screenshot.cpp
@@ -214,10 +214,11 @@ enum class EdgeType
     BOTTOM
 };
 
-static CoordsXY GetEdgeTile(int32_t mapSize, int32_t rotation, EdgeType edgeType, bool visible)
+static CoordsXY GetEdgeTile(TileCoordsXY mapSize, int32_t rotation, EdgeType edgeType, bool visible)
 {
+    // TODO
     int32_t lower = (visible ? 1 : 0) * 32;
-    int32_t upper = (visible ? mapSize - 2 : mapSize - 1) * 32;
+    int32_t upper = (visible ? mapSize.x - 2 : mapSize.x - 1) * 32;
     switch (edgeType)
     {
         default:
@@ -291,12 +292,12 @@ static int32_t GetHighestBaseClearanceZ(const CoordsXY& location)
     return z;
 }
 
-static int32_t GetTallestVisibleTileTop(int32_t mapSize, int32_t rotation)
+static int32_t GetTallestVisibleTileTop(const TileCoordsXY& mapSize, int32_t rotation)
 {
     int32_t minViewY = 0;
-    for (int32_t y = 1; y < mapSize - 1; y++)
+    for (int32_t y = 1; y < mapSize.y - 1; y++)
     {
-        for (int32_t x = 1; x < mapSize - 1; x++)
+        for (int32_t x = 1; x < mapSize.x - 1; x++)
         {
             auto location = TileCoordsXY(x, y).ToCoordsXY();
             int32_t z = GetHighestBaseClearanceZ(location);
@@ -335,7 +336,7 @@ static void ReleaseDPI(rct_drawpixelinfo& dpi)
     dpi.height = 0;
 }
 
-static rct_viewport GetGiantViewport(int32_t mapSize, int32_t rotation, ZoomLevel zoom)
+static rct_viewport GetGiantViewport(const TileCoordsXY& mapSize, int32_t rotation, ZoomLevel zoom)
 {
     // Get the tile coordinates of each corner
     auto leftTileCoords = GetEdgeTile(mapSize, rotation, EdgeType::LEFT, false);
@@ -684,11 +685,11 @@ int32_t cmdline_for_screenshot(const char** argv, int32_t argc, ScreenshotOption
                 customRotation = std::atoi(argv[7]) & 3;
             }
 
-            int32_t mapSize = gMapSize;
+            const auto& mapSize = gMapSize;
             if (resolutionWidth == 0 || resolutionHeight == 0)
             {
-                resolutionWidth = (mapSize * 32 * 2) >> customZoom;
-                resolutionHeight = (mapSize * 32 * 1) >> customZoom;
+                resolutionWidth = (mapSize.x * 32 * 2) >> customZoom;
+                resolutionHeight = (mapSize.y * 32 * 1) >> customZoom;
 
                 resolutionWidth += 8;
                 resolutionHeight += 128;
@@ -701,9 +702,9 @@ int32_t cmdline_for_screenshot(const char** argv, int32_t argc, ScreenshotOption
             if (customLocation)
             {
                 if (centreMapX)
-                    customX = (mapSize / 2) * 32 + 16;
+                    customX = (mapSize.x / 2) * 32 + 16;
                 if (centreMapY)
-                    customY = (mapSize / 2) * 32 + 16;
+                    customY = (mapSize.y / 2) * 32 + 16;
 
                 int32_t z = tile_element_height({ customX, customY });
                 CoordsXYZ coords3d = { customX, customY, z };
diff --git a/src/openrct2/interface/Viewport.cpp b/src/openrct2/interface/Viewport.cpp
index 861af34857..8e4b31c927 100644
--- a/src/openrct2/interface/Viewport.cpp
+++ b/src/openrct2/interface/Viewport.cpp
@@ -249,8 +249,8 @@ CoordsXYZ viewport_adjust_for_map_height(const ScreenCoordsXY& startCoords)
 
         // HACK: This is to prevent the x and y values being set to values outside
         // of the map. This can happen when the height is larger than the map size.
-        auto max = GetMapSizeMinus2();
-        if (pos.x > max && pos.y > max)
+        auto mapSizeMinus2 = GetMapSizeMinus2();
+        if (pos.x > mapSizeMinus2.x && pos.y > mapSizeMinus2.y)
         {
             static constexpr CoordsXY corr[] = {
                 { -1, -1 },
@@ -597,14 +597,15 @@ void viewport_update_position(rct_window* window)
     }
 
     // Clamp to the map maximum value (scenario specific)
-    if (mapCoord.x > GetMapSizeMinus2())
+    auto mapSizeMinus2 = GetMapSizeMinus2();
+    if (mapCoord.x > mapSizeMinus2.x)
     {
-        mapCoord.x = GetMapSizeMinus2();
+        mapCoord.x = mapSizeMinus2.x;
         at_map_edge = 1;
     }
-    if (mapCoord.y > GetMapSizeMinus2())
+    if (mapCoord.y > mapSizeMinus2.y)
     {
-        mapCoord.y = GetMapSizeMinus2();
+        mapCoord.y = mapSizeMinus2.y;
         at_map_edge = 1;
     }
 
diff --git a/src/openrct2/network/NetworkServerAdvertiser.cpp b/src/openrct2/network/NetworkServerAdvertiser.cpp
index 4c6777e5de..73036fe73b 100644
--- a/src/openrct2/network/NetworkServerAdvertiser.cpp
+++ b/src/openrct2/network/NetworkServerAdvertiser.cpp
@@ -298,8 +298,9 @@ private:
             { "players", numPlayers },
         };
 
+        json_t mapSize = { { "x", gMapSize.x - 2 }, { "y", gMapSize.y - 2 } };
         json_t gameInfo = {
-            { "mapSize", gMapSize - 2 },    { "day", gDateMonthTicks },  { "month", gDateMonthsElapsed },
+            { "mapSize", mapSize },         { "day", gDateMonthTicks },  { "month", gDateMonthsElapsed },
             { "guests", gNumGuestsInPark }, { "parkValue", gParkValue },
         };
         if (!(gParkFlags & PARK_FLAGS_NO_MONEY))
diff --git a/src/openrct2/park/ParkFile.cpp b/src/openrct2/park/ParkFile.cpp
index 170ee9f122..b3a86cf73c 100644
--- a/src/openrct2/park/ParkFile.cpp
+++ b/src/openrct2/park/ParkFile.cpp
@@ -891,8 +891,8 @@ namespace OpenRCT2
             auto found = os.ReadWriteChunk(
                 ParkFileChunkType::TILES,
                 [pathToSurfaceMap, pathToQueueSurfaceMap, pathToRailingsMap](OrcaStream::ChunkStream& cs) {
-                    cs.ReadWrite(gMapSize); // x
-                    cs.Write(gMapSize);     // y
+                    cs.ReadWrite(gMapSize.x);
+                    cs.ReadWrite(gMapSize.y);
 
                     if (cs.GetMode() == OrcaStream::Mode::READING)
                     {
diff --git a/src/openrct2/rct1/S4Importer.cpp b/src/openrct2/rct1/S4Importer.cpp
index fa87bad008..da129197a7 100644
--- a/src/openrct2/rct1/S4Importer.cpp
+++ b/src/openrct2/rct1/S4Importer.cpp
@@ -326,7 +326,7 @@ namespace RCT1
 
             // Do map initialisation, same kind of stuff done when loading scenario editor
             auto context = OpenRCT2::GetContext();
-            context->GetGameState()->InitAll(mapSize);
+            context->GetGameState()->InitAll({ mapSize, mapSize });
             gEditorStep = EditorStep::ObjectSelection;
             gParkFlags |= PARK_FLAGS_SHOW_REAL_GUEST_NAMES;
             gScenarioCategory = SCENARIO_CATEGORY_OTHER;
diff --git a/src/openrct2/rct2/S6Importer.cpp b/src/openrct2/rct2/S6Importer.cpp
index a23f5fecbb..011f51ade0 100644
--- a/src/openrct2/rct2/S6Importer.cpp
+++ b/src/openrct2/rct2/S6Importer.cpp
@@ -379,7 +379,7 @@ namespace RCT2
             gCash = ToMoney64(DECRYPT_MONEY(_s6.cash));
             // pad_013587FC
             gParkRatingCasualtyPenalty = _s6.park_rating_casualty_penalty;
-            gMapSize = _s6.map_size;
+            gMapSize = { _s6.map_size, _s6.map_size };
             gSamePriceThroughoutPark = _s6.same_price_throughout
                 | (static_cast<uint64_t>(_s6.same_price_throughout_extended) << 32);
             _suggestedGuestMaximum = _s6.suggested_max_guests;
@@ -1040,7 +1040,7 @@ namespace RCT2
 
         void Initialise()
         {
-            OpenRCT2::GetContext()->GetGameState()->InitAll(_s6.map_size);
+            OpenRCT2::GetContext()->GetGameState()->InitAll({ _s6.map_size, _s6.map_size });
         }
 
         /**
diff --git a/src/openrct2/ride/Ride.cpp b/src/openrct2/ride/Ride.cpp
index 7d5ed7b4a0..954b436506 100644
--- a/src/openrct2/ride/Ride.cpp
+++ b/src/openrct2/ride/Ride.cpp
@@ -5689,9 +5689,9 @@ void determine_ride_entrance_and_exit_locations()
 
 void ride_clear_leftover_entrances(Ride* ride)
 {
-    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize; ++tilePos.x)
+    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize.x; ++tilePos.x)
     {
-        for (tilePos.y = 0; tilePos.y < gMapSize; ++tilePos.y)
+        for (tilePos.y = 0; tilePos.y < gMapSize.y; ++tilePos.y)
         {
             for (auto* entrance : TileElementsView<EntranceElement>(tilePos.ToCoordsXY()))
             {
diff --git a/src/openrct2/ride/RideConstruction.cpp b/src/openrct2/ride/RideConstruction.cpp
index d8dd456703..8a18168a0d 100644
--- a/src/openrct2/ride/RideConstruction.cpp
+++ b/src/openrct2/ride/RideConstruction.cpp
@@ -347,9 +347,9 @@ void Ride::RemovePeeps()
 
 void ride_clear_blocked_tiles(Ride* ride)
 {
-    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize; ++tilePos.x)
+    for (TileCoordsXY tilePos = {}; tilePos.x < gMapSize.x; ++tilePos.x)
     {
-        for (tilePos.y = 0; tilePos.y < gMapSize; ++tilePos.y)
+        for (tilePos.y = 0; tilePos.y < gMapSize.y; ++tilePos.y)
         {
             for (auto* trackElement : TileElementsView<TrackElement>(tilePos.ToCoordsXY()))
             {
diff --git a/src/openrct2/ride/TrackDesign.cpp b/src/openrct2/ride/TrackDesign.cpp
index 1ba3450037..dbd371e252 100644
--- a/src/openrct2/ride/TrackDesign.cpp
+++ b/src/openrct2/ride/TrackDesign.cpp
@@ -1993,10 +1993,10 @@ static bool TrackDesignPlacePreview(TrackDesignState& tds, TrackDesign* td6, mon
     uint8_t backup_rotation = _currentTrackPieceDirection;
     uint32_t backup_park_flags = gParkFlags;
     gParkFlags &= ~PARK_FLAGS_FORBID_HIGH_CONSTRUCTION;
-    int32_t mapSize = gMapSize << 4;
+    auto mapSize = TileCoordsXY{ gMapSize.x / 16, gMapSize.y / 16 };
 
     _currentTrackPieceDirection = 0;
-    int32_t z = TrackDesignGetZPlacement(tds, td6, GetOrAllocateRide(PreviewRideId), { mapSize, mapSize, 16 });
+    int32_t z = TrackDesignGetZPlacement(tds, td6, GetOrAllocateRide(PreviewRideId), { mapSize.x, mapSize.y, 16 });
 
     if (tds.HasScenery)
     {
@@ -2013,7 +2013,7 @@ static bool TrackDesignPlacePreview(TrackDesignState& tds, TrackDesign* td6, mon
     }
 
     auto res = TrackDesignPlaceVirtual(
-        tds, td6, PTD_OPERATION_PLACE_TRACK_PREVIEW, placeScenery, ride, { mapSize, mapSize, z });
+        tds, td6, PTD_OPERATION_PLACE_TRACK_PREVIEW, placeScenery, ride, { mapSize.x, mapSize.y, z });
     gParkFlags = backup_park_flags;
 
     if (res.Error == GameActions::Status::Ok)
@@ -2148,7 +2148,7 @@ static void TrackDesignPreviewClearMap()
 {
     auto numTiles = MAXIMUM_MAP_SIZE_TECHNICAL * MAXIMUM_MAP_SIZE_TECHNICAL;
 
-    gMapSize = 256;
+    gMapSize = { 256, 256 };
 
     // Reserve ~8 elements per tile
     std::vector<TileElement> tileElements;
diff --git a/src/openrct2/scripting/Duktape.hpp b/src/openrct2/scripting/Duktape.hpp
index a31c5a86de..abf01f670f 100644
--- a/src/openrct2/scripting/Duktape.hpp
+++ b/src/openrct2/scripting/Duktape.hpp
@@ -336,6 +336,14 @@ namespace OpenRCT2::Scripting
         return dukCoords.Take();
     }
 
+    template<> DukValue inline ToDuk(duk_context* ctx, const TileCoordsXY& coords)
+    {
+        DukObject dukCoords(ctx);
+        dukCoords.Set("x", coords.x);
+        dukCoords.Set("y", coords.y);
+        return dukCoords.Take();
+    }
+
     template<> DukValue inline ToDuk(duk_context* ctx, const ScreenCoordsXY& coords)
     {
         DukObject dukCoords(ctx);
diff --git a/src/openrct2/scripting/bindings/world/ScMap.cpp b/src/openrct2/scripting/bindings/world/ScMap.cpp
index dec9bec14d..ef562464c9 100644
--- a/src/openrct2/scripting/bindings/world/ScMap.cpp
+++ b/src/openrct2/scripting/bindings/world/ScMap.cpp
@@ -42,7 +42,7 @@ namespace OpenRCT2::Scripting
 
     DukValue ScMap::size_get() const
     {
-        return ToDuk(_context, CoordsXY{ gMapSize, gMapSize });
+        return ToDuk(_context, gMapSize);
     }
 
     int32_t ScMap::numRides_get() const
diff --git a/src/openrct2/title/TitleScreen.cpp b/src/openrct2/title/TitleScreen.cpp
index 669d53fdaf..8be1139caa 100644
--- a/src/openrct2/title/TitleScreen.cpp
+++ b/src/openrct2/title/TitleScreen.cpp
@@ -129,7 +129,7 @@ void TitleScreen::Load()
     GetContext()->GetNetwork().Close();
 #endif
     OpenRCT2::Audio::StopAll();
-    GetContext()->GetGameState()->InitAll(150);
+    GetContext()->GetGameState()->InitAll({ 150, 150 });
     viewport_init_all();
     context_open_window(WC_MAIN_WINDOW);
     CreateWindows();
@@ -335,7 +335,7 @@ bool TitleScreen::TryLoadSequence(bool loadPreview)
         _loadedTitleSequenceId = SIZE_MAX;
         if (!loadPreview)
         {
-            GetContext()->GetGameState()->InitAll(150);
+            GetContext()->GetGameState()->InitAll({ 150, 150 });
         }
         return false;
     }
diff --git a/src/openrct2/world/Map.cpp b/src/openrct2/world/Map.cpp
index 37e2598d71..716d28afa5 100644
--- a/src/openrct2/world/Map.cpp
+++ b/src/openrct2/world/Map.cpp
@@ -90,7 +90,7 @@ uint8_t gMapSelectArrowDirection;
 TileCoordsXY gWidePathTileLoopPosition;
 uint16_t gGrassSceneryTileLoopPosition;
 
-int32_t gMapSize;
+TileCoordsXY gMapSize;
 int32_t gMapBaseZ;
 
 std::vector<CoordsXY> gMapSelectionTiles;
@@ -113,7 +113,7 @@ static TilePointerIndex<TileElement> _tileIndexStash;
 static std::vector<TileElement> _tileElementsStash;
 static size_t _tileElementsInUse;
 static size_t _tileElementsInUseStash;
-static int32_t _mapSizeStash;
+static TileCoordsXY _mapSizeStash;
 static int32_t _currentRotationStash;
 
 void StashMap()
@@ -419,7 +419,7 @@ BannerElement* map_get_banner_element_at(const CoordsXYZ& bannerPos, uint8_t pos
  *
  *  rct2: 0x0068AB4C
  */
-void map_init(int32_t size)
+void map_init(const TileCoordsXY& size)
 {
     auto numTiles = MAXIMUM_MAP_SIZE_TECHNICAL * MAXIMUM_MAP_SIZE_TECHNICAL;
 
@@ -792,7 +792,8 @@ bool map_is_location_valid(const CoordsXY& coords)
 
 bool map_is_edge(const CoordsXY& coords)
 {
-    return (coords.x < 32 || coords.y < 32 || coords.x >= GetMapSizeUnits() || coords.y >= GetMapSizeUnits());
+    auto mapSizeUnits = GetMapSizeUnits();
+    return (coords.x < 32 || coords.y < 32 || coords.x >= mapSizeUnits.x || coords.y >= mapSizeUnits.y);
 }
 
 bool map_can_build_at(const CoordsXYZ& loc)
@@ -1009,8 +1010,9 @@ int32_t tile_element_get_corner_height(const SurfaceElement* surfaceElement, int
 
 uint8_t map_get_lowest_land_height(const MapRange& range)
 {
+    auto mapSizeMax = GetMapSizeMaxXY();
     MapRange validRange = { std::max(range.GetLeft(), 32), std::max(range.GetTop(), 32),
-                            std::min(range.GetRight(), GetMapSizeMaxXY()), std::min(range.GetBottom(), GetMapSizeMaxXY()) };
+                            std::min(range.GetRight(), mapSizeMax.x), std::min(range.GetBottom(), mapSizeMax.y) };
 
     uint8_t min_height = 0xFF;
     for (int32_t yi = validRange.GetTop(); yi <= validRange.GetBottom(); yi += COORDS_XY_STEP)
@@ -1038,8 +1040,9 @@ uint8_t map_get_lowest_land_height(const MapRange& range)
 
 uint8_t map_get_highest_land_height(const MapRange& range)
 {
+    auto mapSizeMax = GetMapSizeMaxXY();
     MapRange validRange = { std::max(range.GetLeft(), 32), std::max(range.GetTop(), 32),
-                            std::min(range.GetRight(), GetMapSizeMaxXY()), std::min(range.GetBottom(), GetMapSizeMaxXY()) };
+                            std::min(range.GetRight(), mapSizeMax.x), std::min(range.GetBottom(), mapSizeMax.y) };
 
     uint8_t max_height = 0;
     for (int32_t yi = validRange.GetTop(); yi <= validRange.GetBottom(); yi += COORDS_XY_STEP)
@@ -1333,9 +1336,9 @@ void map_update_tiles()
         }
 
         // Repeat for each 256x256 block on the map
-        for (int32_t blockY = 0; blockY < gMapSize; blockY += 256)
+        for (int32_t blockY = 0; blockY < gMapSize.y; blockY += 256)
         {
-            for (int32_t blockX = 0; blockX < gMapSize; blockX += 256)
+            for (int32_t blockX = 0; blockX < gMapSize.x; blockX += 256)
             {
                 auto mapPos = TileCoordsXY{ blockX + x, blockY + y }.ToCoordsXY();
                 auto* surfaceElement = map_get_surface_element_at(mapPos);
@@ -1406,7 +1409,7 @@ void map_restore_provisional_elements()
  */
 void map_remove_out_of_range_elements()
 {
-    int32_t mapMaxXY = GetMapSizeMaxXY();
+    auto mapSizeMax = GetMapSizeMaxXY();
 
     // Ensure that we can remove elements
     //
@@ -1416,11 +1419,11 @@ void map_remove_out_of_range_elements()
     bool buildState = gCheatsBuildInPauseMode;
     gCheatsBuildInPauseMode = true;
 
-    for (int32_t y = 0; y < MAXIMUM_MAP_SIZE_BIG; y += COORDS_XY_STEP)
+    for (int32_t y = MAXIMUM_MAP_SIZE_BIG - COORDS_XY_STEP; y >= 0; y -= COORDS_XY_STEP)
     {
-        for (int32_t x = 0; x < MAXIMUM_MAP_SIZE_BIG; x += COORDS_XY_STEP)
+        for (int32_t x = MAXIMUM_MAP_SIZE_BIG - COORDS_XY_STEP; x >= 0; x -= COORDS_XY_STEP)
         {
-            if (x == 0 || y == 0 || x >= mapMaxXY || y >= mapMaxXY)
+            if (x == 0 || y == 0 || x >= mapSizeMax.x || y >= mapSizeMax.y)
             {
                 // Note this purposely does not use LandSetRightsAction as X Y coordinates are outside of normal range.
                 auto surfaceElement = map_get_surface_element_at(CoordsXY{ x, y });
@@ -1476,19 +1479,15 @@ static void map_extend_boundary_surface_extend_tile(const SurfaceElement& source
 }
 
 /**
- * Copies the terrain and slope from the edge of the map to the new tiles. Used when increasing the size of the map.
- *  rct2: 0x0068AC15
+ * Copies the terrain and slope from the Y edge of the map to the new tiles. Used when increasing the size of the map.
  */
-void map_extend_boundary_surface()
+void map_extend_boundary_surface_y()
 {
-    SurfaceElement *existingTileElement, *newTileElement;
-    int32_t x, y;
-
-    y = gMapSize - 2;
-    for (x = 0; x < MAXIMUM_MAP_SIZE_TECHNICAL; x++)
+    auto y = gMapSize.y - 2;
+    for (auto x = 0; x < MAXIMUM_MAP_SIZE_TECHNICAL; x++)
     {
-        existingTileElement = map_get_surface_element_at(TileCoordsXY{ x, y - 1 }.ToCoordsXY());
-        newTileElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
+        auto existingTileElement = map_get_surface_element_at(TileCoordsXY{ x, y - 1 }.ToCoordsXY());
+        auto newTileElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
 
         if (existingTileElement != nullptr && newTileElement != nullptr)
         {
@@ -1497,18 +1496,22 @@ void map_extend_boundary_surface()
 
         update_park_fences({ x << 5, y << 5 });
     }
+}
 
-    x = gMapSize - 2;
-    for (y = 0; y < MAXIMUM_MAP_SIZE_TECHNICAL; y++)
+/**
+ * Copies the terrain and slope from the X edge of the map to the new tiles. Used when increasing the size of the map.
+ */
+void map_extend_boundary_surface_x()
+{
+    auto x = gMapSize.x - 2;
+    for (auto y = 0; y < MAXIMUM_MAP_SIZE_TECHNICAL; y++)
     {
-        existingTileElement = map_get_surface_element_at(TileCoordsXY{ x - 1, y }.ToCoordsXY());
-        newTileElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
-
+        auto existingTileElement = map_get_surface_element_at(TileCoordsXY{ x - 1, y }.ToCoordsXY());
+        auto newTileElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
         if (existingTileElement != nullptr && newTileElement != nullptr)
         {
             map_extend_boundary_surface_extend_tile(*existingTileElement, *newTileElement);
         }
-
         update_park_fences({ x << 5, y << 5 });
     }
 }
@@ -2304,3 +2307,14 @@ void FixLandOwnershipTilesWithOwnership(std::initializer_list<TileCoordsXY> tile
         }
     }
 }
+
+MapRange ClampRangeWithinMap(const MapRange& range)
+{
+    auto mapSizeMax = GetMapSizeMaxXY();
+    auto aX = std::max<decltype(range.GetLeft())>(32, range.GetLeft());
+    auto bX = std::min<decltype(range.GetRight())>(mapSizeMax.x, range.GetRight());
+    auto aY = std::max<decltype(range.GetTop())>(32, range.GetTop());
+    auto bY = std::min<decltype(range.GetBottom())>(mapSizeMax.y, range.GetBottom());
+    MapRange validRange = MapRange{ aX, aY, bX, bY };
+    return validRange;
+}
diff --git a/src/openrct2/world/Map.h b/src/openrct2/world/Map.h
index 59491ba6f1..1468aac1a6 100644
--- a/src/openrct2/world/Map.h
+++ b/src/openrct2/world/Map.h
@@ -99,20 +99,21 @@ extern const TileCoordsXY TileDirectionDelta[];
 extern TileCoordsXY gWidePathTileLoopPosition;
 extern uint16_t gGrassSceneryTileLoopPosition;
 
-extern int32_t gMapSize;
+extern TileCoordsXY gMapSize;
 extern int32_t gMapBaseZ;
 
-inline int32_t GetMapSizeUnits()
+inline CoordsXY GetMapSizeUnits()
 {
-    return (gMapSize - 1) * COORDS_XY_STEP;
+    return { (gMapSize.x - 1) * COORDS_XY_STEP, (gMapSize.y - 1) * COORDS_XY_STEP };
 }
-inline int32_t GetMapSizeMinus2()
+inline CoordsXY GetMapSizeMinus2()
 {
-    return (gMapSize * COORDS_XY_STEP) + (8 * COORDS_XY_STEP - 2);
+    return { (gMapSize.x * COORDS_XY_STEP) + (8 * COORDS_XY_STEP - 2),
+             (gMapSize.y * COORDS_XY_STEP) + (8 * COORDS_XY_STEP - 2) };
 }
-inline int32_t GetMapSizeMaxXY()
+inline CoordsXY GetMapSizeMaxXY()
 {
-    return GetMapSizeUnits() - 1;
+    return GetMapSizeUnits() - CoordsXY{ 1, 1 };
 }
 
 extern uint16_t gMapSelectFlags;
@@ -150,7 +151,7 @@ void StashMap();
 void UnstashMap();
 std::vector<TileElement> GetReorganisedTileElementsWithoutGhosts();
 
-void map_init(int32_t size);
+void map_init(const TileCoordsXY& size);
 
 void map_count_remaining_land_rights();
 void map_strip_ghost_flag_from_elements();
@@ -216,7 +217,8 @@ int32_t map_get_highest_z(const CoordsXY& loc);
 bool tile_element_wants_path_connection_towards(const TileCoordsXYZD& coords, const TileElement* const elementToBeRemoved);
 
 void map_remove_out_of_range_elements();
-void map_extend_boundary_surface();
+void map_extend_boundary_surface_x();
+void map_extend_boundary_surface_y();
 
 bool map_large_scenery_sign_set_colour(const CoordsXYZD& signPos, int32_t sequence, uint8_t mainColour, uint8_t textColour);
 void wall_remove_at(const CoordsXYRangedZ& wallPos);
@@ -259,3 +261,4 @@ uint16_t check_max_allowable_land_rights_for_tile(const CoordsXYZ& tileMapPos);
 void FixLandOwnershipTiles(std::initializer_list<TileCoordsXY> tiles);
 void FixLandOwnershipTilesWithOwnership(
     std::initializer_list<TileCoordsXY> tiles, uint8_t ownership, bool doNotDowngrade = false);
+MapRange ClampRangeWithinMap(const MapRange& range);
diff --git a/src/openrct2/world/MapGen.cpp b/src/openrct2/world/MapGen.cpp
index 8787e543db..d08004b745 100644
--- a/src/openrct2/world/MapGen.cpp
+++ b/src/openrct2/world/MapGen.cpp
@@ -119,7 +119,7 @@ void mapgen_generate_blank(mapgen_settings* settings)
     int32_t x, y;
     map_clear_all_elements();
 
-    map_init(settings->mapSize);
+    map_init({ settings->mapSize, settings->mapSize });
     for (y = 1; y < settings->mapSize - 1; y++)
     {
         for (x = 1; x < settings->mapSize - 1; x++)
@@ -167,7 +167,7 @@ void mapgen_generate(mapgen_settings* settings)
     map_clear_all_elements();
 
     // Initialise the base map
-    map_init(mapSize);
+    map_init({ mapSize, mapSize });
     for (auto y = 1; y < mapSize - 1; y++)
     {
         for (auto x = 1; x < mapSize - 1; x++)
@@ -320,9 +320,9 @@ static void mapgen_place_trees()
     std::vector<TileCoordsXY> availablePositions;
 
     // Create list of available tiles
-    for (int32_t y = 1; y < gMapSize - 1; y++)
+    for (int32_t y = 1; y < gMapSize.y - 1; y++)
     {
-        for (int32_t x = 1; x < gMapSize - 1; x++)
+        for (int32_t x = 1; x < gMapSize.x - 1; x++)
         {
             auto* surfaceElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
             if (surfaceElement == nullptr)
@@ -398,13 +398,9 @@ static void mapgen_place_trees()
  */
 static void mapgen_set_water_level(int32_t waterLevel)
 {
-    int32_t x, y, mapSize;
-
-    mapSize = gMapSize;
-
-    for (y = 1; y < mapSize - 1; y++)
+    for (int32_t y = 1; y < gMapSize.y - 1; y++)
     {
-        for (x = 1; x < mapSize - 1; x++)
+        for (int32_t x = 1; x < gMapSize.x - 1; x++)
         {
             auto surfaceElement = map_get_surface_element_at(TileCoordsXY{ x, y }.ToCoordsXY());
             if (surfaceElement != nullptr && surfaceElement->base_height < waterLevel)
@@ -781,7 +777,8 @@ void mapgen_generate_from_heightmap(mapgen_settings* settings)
     // Make a copy of the original height map that we can edit
     auto dest = _heightMapData.mono_bitmap;
 
-    map_init(_heightMapData.width + 2); // + 2 for the black tiles around the map
+    auto maxSize = static_cast<int32_t>(_heightMapData.width + 2); // + 2 for the black tiles around the map
+    map_init({ maxSize, maxSize });
 
     if (settings->smooth_height_map)
     {