[url="http://en.wikipedia.org/wiki/Chattanooga,_Tennessee"]Chattanooga, Tennessee[/url] fits the criteria minus the swamp. It's within the vicinity of a forest, near a large body of water, isn't a primary target in WW3 so the area is pretty much intact, south enough that it's warm even during global cooling. The city size leaves a lot to be desired but it doesn't really matter in the long run of the RP.