In your ancap society, I guess the land is still owned in the hard, state defined sense at the bottom, which make it different from the ideal master-free society (where everybody is the sovereign of his own self-kingdom). Anyway, it is an interesting approximation of a free society.
Land here is acquired by purchasing or homesteading. Most countries allow for homesteading and the loss of land that is neglected. Many countries allow for water right claims, and other common law rights such as the right to travel, even through private property if other ways are not assessable. The United States is really just the outlier with all the changes over the years removing the rights to homesteading which ended in 1976 (and in 1986 for Alaska) . Land rights are transient and most anarcho-capitalists believe in such a principle. We believe property rights as an extension of self ownership which can be gained or lost. The details as how the state determines property rights and homesteading is far from perfect but also not very different than how it would function in an anarchist society. Anarchists believe in governments and laws , just not in
state governments with monopolies of force. Costa Rica is fairly close to that ideal being that it has abolished the military over 60 years ago, thus homesteading is determined by local witnesses and evidence provided to a local judge. Within a purer anarchist society this judge would probably be represented by a group of volunteers and upstanding community members all of the community agreed upon that took on a temporary role of arbitration.
Even more interesting...