Mr. Steinbrenner, I think Federation Earth could rebuild and repopulate whole cities or what we think of as countries pretty quickly. Future Earth could take in billions of immigrants without it strain. If there are any limits to the sizes or placements of cities on the planet, I think they're so by choice.
Timo, there's also no reason to think whatever the sizes of cities are above-ground that they're not also massive below-ground. Heck, if Abrams' ships are twice the size of TOS', why not his cities? This link especially from my last reply makes me think that contemporary buildings casually thrown in could have more to them than we might think. ...It would also be easier to carve out if the building above were a reconstruction of a WWIII-destroyed landmark, though Federation tech could probably hollow it out without disturbing a butterfly above-ground.
Timo, there's also no reason to think whatever the sizes of cities are above-ground that they're not also massive below-ground. Heck, if Abrams' ships are twice the size of TOS', why not his cities? This link especially from my last reply makes me think that contemporary buildings casually thrown in could have more to them than we might think. ...It would also be easier to carve out if the building above were a reconstruction of a WWIII-destroyed landmark, though Federation tech could probably hollow it out without disturbing a butterfly above-ground.