Timetravelling! The map is splitted into half. The other side is past other is future and you can switch between them with timemachines and have to stop some badguy who changes the past to invade whole world... Or something stuff like that.
[right][snapback]527337[/snapback][/right]
pretty neat idea. although i wouldn't recommend splitting the map in half, because firstly, the terrain will take a very long time to equally create on both sides, and also, it takes away the feeling of realism. instead, id suggest taking advantage of your location layer, for replacing units/buildings where relevant. if you use alot of units, create spawning and patrol triggers.
that is, if you choose to build this map.