I think the thing missing from the other replies to your comment is the question of who owns your hypothetical forest. If everyone agrees that the forest is pri

I think the thing missing from the other replies to your comment is the question of who owns your hypothetical forest. If everyone agrees that the forest is privately owned by some particular person, then I agree with you that your nationality shouldn't prevent you from buying a part of the forest from that person and living there. If the forest is publicly owned (i.e. jointly owned by all French citizens) then it's precisely the job of the French government to decide if you can live there. Of course you could also ask about the example of a forest that was "unowned" (although these days to find land without a property claim you would have to go into space). But personally I'm inclined to treat unowned property the same as publicly owned (by the entire world). Everyone has an equal claim to it. Therefore, again, you would have to find some price at which the government was willing to sell it to you.