I came across this website (www.mapisimo.com), it allows every human to own a little square (30x30 aprox) on the earth's surface. Once you own a land parcel it's yours forever.
Unfortunately most interesting places (Eiffel Tower, Statue of Liberty, etc) are already taken, but you may find that places of local interest (city or neighbourhood) are unoccupied yet.

[Unlinked – Tony]