It'a log cabin home constructed entirely from one singular hollowed-out redwood log. Well, what do you want for free?
It is kind of interesting, actually - even though the log is cramped (or cozy, depending on your perspective) and dark and there really isn't anything to see or say other than "yep, that's a house inside a giant log, alright". It's all part of life's rich pageant.
(Life in a log isn't perfect, though - the roof evidently leaks, hence the giant blue tarp draped over the entire shebang.)