diff --git a/src/scenario.h b/src/scenario.h
index 339e4b088f..41d3ffa3b4 100644
--- a/src/scenario.h
+++ b/src/scenario.h
@@ -434,6 +434,7 @@ typedef struct {
 	uint8 category;
 	uint8 source_game;
 	sint16 source_index;
+	uint16 sc_id;
 
 	// Objective
 	uint8 objective_type;
@@ -448,6 +449,7 @@ typedef struct {
 
 typedef struct {
 	const utf8 *title;
+	uint8 id;
 	uint8 source;
 	sint32 index;
 	uint8 category;
diff --git a/src/scenario_list.c b/src/scenario_list.c
index 2efe09d81b..3604a3d806 100644
--- a/src/scenario_list.c
+++ b/src/scenario_list.c
@@ -170,10 +170,12 @@ static void scenario_list_add(const utf8 *path, uint64 timestamp)
 	// Look up and store information regarding the origins of this scenario.
 	source_desc desc;
 	if (scenario_get_source_desc(newEntry->name, &desc)) {
+		newEntry->sc_id = desc.id;
 		newEntry->source_index = desc.index;
 		newEntry->source_game = desc.source;
 		newEntry->category = desc.category;
 	} else {
+		newEntry->sc_id = SC_UNIDENTIFIED;
 		newEntry->source_index = -1;
 		if (newEntry->category == SCENARIO_CATEGORY_REAL) {
 			newEntry->source_game = SCENARIO_SOURCE_REAL;
diff --git a/src/scenario_sources.c b/src/scenario_sources.c
index 7ad8858213..90fddcd7e8 100644
--- a/src/scenario_sources.c
+++ b/src/scenario_sources.c
@@ -219,6 +219,7 @@ bool scenario_get_source_desc(const utf8 *name, source_desc *outDesc)
 			const scenario_title_desc *desc = &ScenarioTitlesBySource[i].titles[j];
 			if (_strcmpi(name, desc->title) == 0) {
 				outDesc->title = desc->title;
+				outDesc->id = desc->id;
 				outDesc->source = i;
 				outDesc->index = currentIndex;
 				outDesc->category = desc->category;
@@ -228,6 +229,8 @@ bool scenario_get_source_desc(const utf8 *name, source_desc *outDesc)
 		}
 	}
 
+	outDesc->title = NULL;
+	outDesc->id = SC_UNIDENTIFIED;
 	outDesc->source = SCENARIO_SOURCE_OTHER;
 	outDesc->index = -1;
 	outDesc->category = SCENARIO_CATEGORY_OTHER;
@@ -244,6 +247,7 @@ bool scenario_get_source_desc_by_id(uint8 id, source_desc *outDesc)
 			const scenario_title_desc *desc = &ScenarioTitlesBySource[i].titles[j];
 			if (id == desc->id) {
 				outDesc->title = desc->title;
+				outDesc->id = desc->id;
 				outDesc->source = i;
 				outDesc->index = currentIndex;
 				outDesc->category = desc->category;
@@ -253,6 +257,8 @@ bool scenario_get_source_desc_by_id(uint8 id, source_desc *outDesc)
 		}
 	}
 
+	outDesc->title = NULL;
+	outDesc->id = SC_UNIDENTIFIED;
 	outDesc->source = SCENARIO_SOURCE_OTHER;
 	outDesc->index = -1;
 	outDesc->category = SCENARIO_CATEGORY_OTHER;
diff --git a/src/windows/title_scenarioselect.c b/src/windows/title_scenarioselect.c
index 1b6e706acf..373c2d58ff 100644
--- a/src/windows/title_scenarioselect.c
+++ b/src/windows/title_scenarioselect.c
@@ -506,6 +506,11 @@ static void initialise_list_items(rct_window *w)
 	int length = 0;
 	_listItems = malloc(capacity * sizeof(sc_list_item));
 
+	// Mega park unlock
+	const uint32 rct1RequiredCompletedScenarios = (1 << SC_MEGA_PARK) - 1;
+	uint32 rct1CompletedScenarios = 0;
+	int megaParkListItemIndex = -1;
+
 	int numUnlocks = INITIAL_NUM_UNLOCKED_SCENARIOS;
 	uint8 currentHeading = UINT8_MAX;
 	for (int i = 0; i < gScenarioListCount; i++) {
@@ -555,6 +560,16 @@ static void initialise_list_items(rct_window *w)
 			listItem->scenario.is_locked = numUnlocks <= 0;
 			if (scenario->highscore == NULL) {
 				numUnlocks--;
+			} else {
+				// Mark RCT1 scenario as completed
+				if (scenario->sc_id < SC_MEGA_PARK) {
+					rct1CompletedScenarios |= 1 << scenario->sc_id;
+				}
+			}
+
+			// If scenario is Mega Park, keep a reference to it
+			if (scenario->sc_id == SC_MEGA_PARK) {
+				megaParkListItemIndex = length - 1;
 			}
 		} else {
 			listItem->scenario.is_locked = false;
@@ -564,6 +579,31 @@ static void initialise_list_items(rct_window *w)
 	length++;
 	_listItems = realloc(_listItems, length * sizeof(sc_list_item));
 	_listItems[length - 1].type = LIST_ITEM_TYPE_END;
+
+	// Mega park handling
+	if (megaParkListItemIndex != -1) {
+		bool megaParkLocked = (rct1CompletedScenarios & rct1RequiredCompletedScenarios) != rct1RequiredCompletedScenarios;
+		_listItems[megaParkListItemIndex].scenario.is_locked = megaParkLocked;
+#ifdef HIDE_MEGA_PARK
+		if (megaParkLocked) {
+			// Remove mega park
+			int remainingItems = length - megaParkListItemIndex - 1;
+			memmove(&_listItems[megaParkListItemIndex], &_listItems[megaParkListItemIndex + 1], remainingItems);
+
+			// Remove empty headings
+			int i = 0;
+			for (sc_list_item *listItem = _listItems; listItem->type != LIST_ITEM_TYPE_END; listItem++) {
+				if (listItem->type == LIST_ITEM_TYPE_HEADING && (listItem + 1)->type != LIST_ITEM_TYPE_SCENARIO) {
+					remainingItems = length - i - 1;
+					memmove(&_listItems[i], &_listItems[i + 1], remainingItems);
+					listItem--;
+				} else {
+					i++;
+				}
+			}
+		}
+#endif
+	}
 }
 
 static bool is_scenario_visible(rct_window *w, scenario_index_entry *scenario)