[fragmede]

land is a pretty broad stroke though, and there are obviously specific areas of land that aren't self-sustaining, so it depends on how you want to slice it. So if these end up being only slightly more self-sustaining as, say McMurdo base in Antarctica, it doesn't seem like a showstopper for habitation.

[marssaxman]

Las Vegas, for that matter, cannot possibly exist in the environment where it was built without constant support from habitable places.