Being able to increase the tiles number up to 25 is just something that was stated to be true. Again, I can't think of specific sources, but certainly Arumba didn't just made a mistake. Twice."How big can the maps be?(...) The cities can be 36 square km, and not necessarily in a square. However there is an option to uncouple the limitation and go bigger, dependant on the player’s hardware.""18/02/2015 at 01:18 Joshua Northey says:Then default mode is up to 9 2x2km tiles. So a 6x6km square. By hat is actually plenty large for the core I most cities and the scale of a game like this. Then with mods you can unlock it to 10x10km and 25 tiles. That is quite large.""So we know that we are allowed to choose 9 of the 25 tiles to make our city, but through modding we should be able to use all 25 tiles (or 100 km^2 area).""Vanilla Cities:Skylines will give you 36 km2 to play with. This is based on 9 of 25 tiles being unlocked during game play (Each tile is 2 km x 2 km).Mods will be able to unlock all 25 tiles (if your computer can handle it) giving you 100 km2.This is pretty close to the original Cities XL 110 km2."Not official sources, but all those people must have heard somewhere that increasing our cities' sizes would be indeed possible and easy, just like all of us.