Man can will nothing unless he has first understood that he must count on no one but himself; that he is alone, abandoned on earth in the midst of his infinite responsibilities, without help, with no other aim than the one he sets himself, with no other destiny than the one he forges for himself on this earth.
- Jean Paul Sartre
It may be that there are more formerly inhabited places than currently inhabited places. The USA is lucky in that most abandoned places are abandoned for reasons other than a war swept over the place. Cyprus isn't so lucky, nor are a lot of other places.
There is an astonishing set of pictures of a dozen or more abandoned cities. Abandoned recently, not a thousand years ago. Well worth your time, in a bittersweet there but for the grace of God sort of way.