diff --git a/src/world/map.c b/src/world/map.c
index c02691b09c..0194509789 100644
--- a/src/world/map.c
+++ b/src/world/map.c
@@ -2051,13 +2051,473 @@ void game_command_lower_land(int* eax, int* ebx, int* ecx, int* edx, int* esi, i
 	);
 }
 
+static int map_get_corner_height(rct_map_element *mapElement, int slopeMask)
+{
+	int z = mapElement->base_height;
+	int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+	switch (slopeMask) {
+	case 1:
+		if (slope & 1) {
+			z += 2;
+			if (slope == 27) {
+				z += 2;
+			}
+		}
+		break;
+	case 2:
+		if (slope & 2) {
+			z += 2;
+			if (slope == 23) {
+				z += 2;
+			}
+		}
+		break;
+	case 4:
+		if (slope & 4) {
+			z += 2;
+			if (slope == 30) {
+				z += 2;
+			}
+		}
+		break;
+	case 8:
+		if (slope & 8) {
+			z += 2;
+			if (slope == 29) {
+				z += 2;
+			}
+		}
+		break;
+	}
+	return z;
+}
+
+/**
+ *
+ *  rct2: 0x0068C3B2
+ */
+static money32 sub_68C3B2(uint8 flags, int x, int y, uint8 targetBaseZ, uint8 minBaseZ)
+{
+	// Check if inside map bounds
+	if (x < 0 || y < 0 || x >= (256 * 32) || y >= (256 * 32)) {
+		return MONEY32_UNDEFINED;
+	}
+
+	// Get height of tile
+	rct_map_element *mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+	uint8 baseZ = map_get_corner_height(mapElement, 1);
+
+	// Check if tile is same height as target tile
+	if (baseZ == targetBaseZ) {
+		// No need to raise or lower
+		return MONEY32_UNDEFINED;
+	}
+
+	uint8 style;
+	if (targetBaseZ <= baseZ) {
+		baseZ = baseZ - targetBaseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_lower_styles[0][slope];
+		if (style & 0x20) {
+			targetBaseZ -= 2;
+			style &= ~0x20;
+		}
+	} else {
+		baseZ = targetBaseZ - baseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_raise_styles[0][slope];
+		if ((style & 0x20) != 0) {
+			targetBaseZ += 2;
+			style &= ~0x20;
+		}
+	}
+
+	return game_do_command(x, flags, y, targetBaseZ | (style << 8), GAME_COMMAND_SET_LAND_HEIGHT, 0, 0);
+}
+
+/**
+ *
+ *  rct2: 0x0068C47A
+ */
+static money32 sub_68C47A(uint8 flags, int x, int y, uint8 targetBaseZ, uint8 minBaseZ)
+{
+	// Check if inside map bounds
+	if (x < 0 || y < 0 || x >= (256 * 32) || y >= (256 * 32)) {
+		return MONEY32_UNDEFINED;
+	}
+
+	// Get height of tile
+	rct_map_element *mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+	uint8 baseZ = map_get_corner_height(mapElement, 2);
+
+	// Check if tile is same height as target tile
+	if (baseZ == targetBaseZ) {
+		// No need to raise or lower
+		return MONEY32_UNDEFINED;
+	}
+
+	uint8 style;
+	if (targetBaseZ <= baseZ) {
+		baseZ = baseZ - targetBaseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_lower_styles[1][slope];
+		if (style & 0x20) {
+			targetBaseZ -= 2;
+			style &= ~0x20;
+		}
+	} else {
+		baseZ = targetBaseZ - baseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_raise_styles[1][slope];
+		if ((style & 0x20) != 0) {
+			targetBaseZ += 2;
+			style &= ~0x20;
+		}
+	}
+
+	return game_do_command(x, flags, y, targetBaseZ | (style << 8), GAME_COMMAND_SET_LAND_HEIGHT, 0, 0);
+}
+
+/**
+ *
+ *  rct2: 0x0068C222
+ */
+static money32 sub_68C222(uint8 flags, int x, int y, uint8 targetBaseZ, uint8 minBaseZ)
+{
+	// Check if inside map bounds
+	if (x < 0 || y < 0 || x >= (256 * 32) || y >= (256 * 32)) {
+		return MONEY32_UNDEFINED;
+	}
+
+	// Get height of tile
+	rct_map_element *mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+	uint8 baseZ = map_get_corner_height(mapElement, 4);
+
+	// Check if tile is same height as target tile
+	if (baseZ == targetBaseZ) {
+		// No need to raise or lower
+		return MONEY32_UNDEFINED;
+	}
+
+	uint8 style;
+	if (targetBaseZ <= baseZ) {
+		baseZ = baseZ - targetBaseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_lower_styles[2][slope];
+		if (style & 0x20) {
+			targetBaseZ -= 2;
+			style &= ~0x20;
+		}
+	} else {
+		baseZ = targetBaseZ - baseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_raise_styles[2][slope];
+		if ((style & 0x20) != 0) {
+			targetBaseZ += 2;
+			style &= ~0x20;
+		}
+	}
+
+	return game_do_command(x, flags, y, targetBaseZ | (style << 8), GAME_COMMAND_SET_LAND_HEIGHT, 0, 0);
+}
+
+/**
+ *
+ *  rct2: 0x0068C2EA
+ */
+static money32 sub_68C2EA(uint8 flags, int x, int y, uint8 targetBaseZ, uint8 minBaseZ)
+{
+	// Check if inside map bounds
+	if (x < 0 || y < 0 || x >= (256 * 32) || y >= (256 * 32)) {
+		return MONEY32_UNDEFINED;
+	}
+
+	// Get height of tile
+	rct_map_element *mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+	uint8 baseZ = map_get_corner_height(mapElement, 8);
+
+	// Check if tile is same height as target tile
+	if (baseZ == targetBaseZ) {
+		// No need to raise or lower
+		return MONEY32_UNDEFINED;
+	}
+
+	uint8 style;
+	if (targetBaseZ <= baseZ) {
+		baseZ = baseZ - targetBaseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_lower_styles[3][slope];
+		if (style & 0x20) {
+			targetBaseZ -= 2;
+			style &= ~0x20;
+		}
+	} else {
+		baseZ = targetBaseZ - baseZ;
+		if (baseZ <= minBaseZ) {
+			return MONEY32_UNDEFINED;
+		}
+		targetBaseZ = mapElement->base_height;
+		int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+		style = map_element_raise_styles[3][slope];
+		if ((style & 0x20) != 0) {
+			targetBaseZ += 2;
+			style &= ~0x20;
+		}
+	}
+
+	return game_do_command(x, flags, y, targetBaseZ | (style << 8), GAME_COMMAND_SET_LAND_HEIGHT, 0, 0);
+}
+
 /**
  *
  *  rct2: 0x0068BC01
  */
 void game_command_smooth_land(int* eax, int* ebx, int* ecx, int* edx, int* esi, int* edi, int* ebp)
 {
-	RCT2_CALLFUNC_X(0x0068BC01, eax, ebx, ecx, edx, esi, edi, ebp);
+	// RCT2_CALLFUNC_X(0x0068BC01, eax, ebx, ecx, edx, esi, edi, ebp); return;
+
+	int flags = *ebx & 0xFF;
+	int centreX = *eax & 0xFFFF;
+	int centreY = *ecx & 0xFFFF;
+	int centreZ = map_element_height(centreX, centreY);
+	int mapLeftRight = *edx;
+	int mapTopBottom = *ebp;
+	int mapLeft = mapLeftRight & 0xFFFF;
+	int mapTop = mapTopBottom & 0xFFFF;
+	int mapRight = mapLeftRight >> 16;
+	int mapBottom = mapTopBottom >> 16;
+
+	int subCommand = *edi;
+	int subGameCommandType = *edi == 1 ? GAME_COMMAND_RAISE_LAND : GAME_COMMAND_LOWER_LAND;
+
+	// Play sound (only once)
+	if ((flags & GAME_COMMAND_FLAG_APPLY) && RCT2_GLOBAL(0x009A8C28, uint8) == 1) {
+		sound_play_panned(SOUND_PLACE_ITEM, 0x8001, centreX, centreY, centreZ);
+	}
+
+	money32 totalCost = 0;
+
+	// First raise / lower the centre tile
+	money32 result;
+	result = game_do_command(centreX, flags, centreY, mapLeftRight, subGameCommandType, 4, mapTopBottom);
+	if (result != MONEY32_UNDEFINED) {
+		totalCost += result;
+	}
+
+	int x, y, z;
+	rct_map_element *mapElement;
+
+	x = mapLeft;
+	y = mapTop;
+	mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+	int slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+	if (slope != 0) {
+		int command = subCommand == 0xFFFF ? GAME_COMMAND_RAISE_LAND : GAME_COMMAND_LOWER_LAND;
+		result = game_do_command(centreX, flags, centreY, mapLeftRight, command, 4, mapTopBottom);
+		if (result != MONEY32_UNDEFINED) {
+			totalCost += result;
+		}
+
+		x = mapLeft;
+		y = mapTop;
+		mapElement = map_get_surface_element_at(x >> 5, y >> 5);
+		slope = mapElement->properties.surface.slope & MAP_ELEMENT_SLOPE_MASK;
+
+		*ebx = totalCost * 4;
+		RCT2_GLOBAL(RCT2_ADDRESS_NEXT_EXPENDITURE_TYPE, uint8) = RCT_EXPENDITURE_TYPE_LANDSCAPING * 4;
+		RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_X, uint32) = centreX;
+		RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_Y, uint32) = centreY;
+		RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_Z, uint32) = centreZ;
+		return;
+	}
+
+	x = mapLeft;
+	y = mapTop;
+	int bx = ((mapRight - mapLeft) >> 5) - 1;
+	sint8 byte_F1AD5C = -2;
+
+	for (;;) {
+		byte_F1AD5C += 2;
+		bx += 2;
+		x -= 32;
+		y -= 32;
+		if (bx > 64) {
+			*ebx = totalCost * 4;
+			RCT2_GLOBAL(RCT2_ADDRESS_NEXT_EXPENDITURE_TYPE, uint8) = RCT_EXPENDITURE_TYPE_LANDSCAPING * 4;
+			RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_X, uint32) = centreX;
+			RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_Y, uint32) = centreY;
+			RCT2_GLOBAL(RCT2_ADDRESS_COMMAND_MAP_Z, uint32) = centreZ;
+			return;
+		}
+
+		sint8 minZ = (byte_F1AD5C << 1) & 0xFF;
+
+		// Corner (North-West)
+		mapElement = map_get_surface_element_at(mapLeft >> 5, mapTop >> 5);
+		z = map_get_corner_height(mapElement, 4);
+		result = sub_68C3B2(flags, x, y, z, minZ);
+		if (result != MONEY32_UNDEFINED) {
+			totalCost += result;
+		}
+		y += 32;
+
+		// Side (West)
+		for (int i = 0; i < bx; i++) {
+			int y2 = clamp(mapTop, y, mapBottom);
+			mapElement = map_get_surface_element_at(mapLeft >> 5, y2 >> 5);
+			z = map_get_corner_height(mapElement, 4);
+			result = sub_68C47A(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+			minZ -= 2;
+			if (y >= mapTop) {
+				minZ += 2;
+				if (y > mapBottom) {
+					minZ += 2;
+				}
+			}
+			z = map_get_corner_height(mapElement, 8);
+			result = sub_68C3B2(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+
+			y += 32;
+		}
+
+		// Corner (South-West)
+		mapElement = map_get_surface_element_at(mapLeft >> 5, mapBottom >> 5);
+		z = map_get_corner_height(mapElement, 8);
+		result = sub_68C47A(flags, x, y, z, minZ);
+		if (result != MONEY32_UNDEFINED) {
+			totalCost += result;
+		}
+		x += 32;
+
+		// Side (South)
+		for (int i = 0; i < bx; i++) {
+			int x2 = clamp(mapLeft, x, mapRight);
+			mapElement = map_get_surface_element_at(x2 >> 5, mapBottom >> 5);
+			z = map_get_corner_height(mapElement, 8);
+			result = sub_68C222(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+			minZ -= 2;
+			if (x >= mapLeft) {
+				minZ += 2;
+				if (x > mapRight) {
+					minZ += 2;
+				}
+			}
+			z = map_get_corner_height(mapElement, 1);
+			result = sub_68C47A(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+
+			x += 32;
+		}
+
+		// Corner (South-East)
+		mapElement = map_get_surface_element_at(mapRight >> 5, mapBottom >> 5);
+		z = map_get_corner_height(mapElement, 1);
+		result = sub_68C222(flags, x, y, z, minZ);
+		if (result != MONEY32_UNDEFINED) {
+			totalCost += result;
+		}
+		y -= 32;
+
+		// Side (East)
+		for (int i = 0; i < bx; i++) {
+			int y2 = clamp(mapTop, y, mapBottom);
+			mapElement = map_get_surface_element_at(mapRight >> 5, y2 >> 5);
+			z = map_get_corner_height(mapElement, 1);
+			result = sub_68C2EA(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+			minZ -= 2;
+			if (y <= mapBottom) {
+				minZ += 2;
+				if (y < mapTop) {
+					minZ += 2;
+				}
+			}
+			z = map_get_corner_height(mapElement, 2);
+			result = sub_68C222(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+
+			y -= 32;
+		}
+
+		// Corner (North-East)
+		mapElement = map_get_surface_element_at(mapRight >> 5, mapTop >> 5);
+		z = map_get_corner_height(mapElement, 2);
+		result = sub_68C2EA(flags, x, y, z, minZ);
+		if (result != MONEY32_UNDEFINED) {
+			totalCost += result;
+		}
+		x -= 32;
+
+		// Side (North)
+		for (int i = 0; i < bx; i++) {
+			int x2 = clamp(mapLeft, x, mapRight);
+			mapElement = map_get_surface_element_at(x2 >> 5, mapTop >> 5);
+			z = map_get_corner_height(mapElement, 2);
+			result = sub_68C3B2(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+			minZ -= 2;
+			if (x <= mapRight) {
+				minZ += 2;
+				if (x < mapLeft) {
+					minZ += 2;
+				}
+			}
+			z = map_get_corner_height(mapElement, 4);
+			result = sub_68C2EA(flags, x, y, z, minZ);
+			if (result != MONEY32_UNDEFINED) {
+				totalCost += result;
+			}
+
+			x -= 32;
+		}
+	}
+
+	*ebx = totalCost;
 }
 
 /**