I think land has probably the least defensible claim to inalienable property. You didn't create it, it'll be here long after you're dead. You have it because the government stole it from a bunch of Indians by force, and it's only the government's continued threat of force that allows you to preserve your claim on it.
I've noticed that anti-tax and anti-government folks tend to focus on rights that are "natural", yet it seems to me that, if we accept the notion that the "naturalness" of certain rights is both real and a measure of their value, the right to broad access to most land currently held as private is more "natural" than the right to buy far more land than one can personally use while preventing all others from using it in any way, unless (maybe) they pay you for the privilege.
The fact that money changed hands and some papers were signed seems irrelevant to the "naturalness" of exclusive access to land, to me—then again, I consider concerns over and arguments revolving around "naturalness" to mostly be a distraction when it comes to figuring out which freedoms I'd prefer to preserve over which others, so maybe I'm a bad judge of these things.
