Mega Cities

There are 4 mega-cities to be found on the map. While the eastern and southern one, are near to the X or Y axis, the northern and western mega city, are more difficult to restore. 
Location:	x: 108	y: -216
Location:	x: 224	y: -8
Location:	x: 8	y: 160
Location:	x: -216	y: 128
All restored mega cities will start at level 30. The only exception is Main Settlement, which will grow into a mega-city after leveling it to level 45.
Mega-Constructors is the only upgrade explicitly for mega-cities. There are a lot others, which will affect them in one or another way.