Are there living cities in the post apocalyptic world? A living steampunk city could be cool.
There are various empires and cities in the world, ranging from small towns to large and elaborate cities and trading hubs. Post-apocalyptically, The Wastes would be an example of a completely dead area, and there are a couple of interesting craters in the southern territories that look like the remains of explosive blasts. Besides that, the whole world is live and kicking.
In terms of Island maps, that would be rather nice to look at, but from a gameplay view they wouldn't work too well- far too open, and you couldn't drop people into the terrain due to the 'landing' mechanic that's present when you hit water.