Parcel of public land. An overworked bureaucrat probably shouldn't be selling those off cheaply, should they? Some private land is even subject to the right to roam*, so the public can still access it.
America bootstrapped its private property market. (No. Bad elephant.) All of her land was "first" public land (or royal land) and then granted to private persons.
There's a big difference between a parcel of private land changing hands, and a parcel of public land becoming private.