diff --git a/src/table/unmovable_land.h b/src/table/unmovable_land.h
--- a/src/table/unmovable_land.h
+++ b/src/table/unmovable_land.h
@@ -125,9 +125,9 @@ static const DrawTileSprites _unmovable_
 
 /** Specification of the original unmovable structures. */
 static const UnmovableSpec _original_unmovable[] = {
-	{ STR_LAI_UNMOVABLE_DESCRIPTION_TRANSMITTER,          0x11,   1,   1 },
-	{ STR_LAI_UNMOVABLE_DESCRIPTION_LIGHTHOUSE,           0x11,   1,   1 },
-	{ STR_TOWN_BUILDING_NAME_STATUE_1,                    0x11,   1,   1 },
-	{ STR_LAI_UNMOVABLE_DESCRIPTION_COMPANY_OWNED_LAND,   0x11,  10,   2 },
-	{ STR_LAI_UNMOVABLE_DESCRIPTION_COMPANY_HEADQUARTERS, 0x22,   1,   1 },
+	{ STR_LAI_UNMOVABLE_DESCRIPTION_TRANSMITTER,          0x11,   1,   1, OBJECT_FLAG_CANNOT_REMOVE | OBJECT_FLAG_REQUIRE_FLAT },
+	{ STR_LAI_UNMOVABLE_DESCRIPTION_LIGHTHOUSE,           0x11,   1,   1, OBJECT_FLAG_CANNOT_REMOVE | OBJECT_FLAG_REQUIRE_FLAT },
+	{ STR_TOWN_BUILDING_NAME_STATUE_1,                    0x11,   1,   1, OBJECT_FLAG_CANNOT_REMOVE },
+	{ STR_LAI_UNMOVABLE_DESCRIPTION_COMPANY_OWNED_LAND,   0x11,  10,   2, OBJECT_FLAG_AUTOREMOVE | OBJECT_FLAG_CLEAR_INCOME | OBJECT_FLAG_HAS_NO_FOUNDATION | OBJECT_FLAG_ALLOW_UNDER_BRIDGE },
+	{ STR_LAI_UNMOVABLE_DESCRIPTION_COMPANY_HEADQUARTERS, 0x22,   1,   1, OBJECT_FLAG_CANNOT_REMOVE },
 };