there is this place in Oregon, southern end wst of the Cascades, that has several little tree houses. They were originally going to run it like a B-n-B or camp ground, but the local authorities (building safety code fucks) closed them down and deemed the houses unsafe. They can not legally 'rent' them out...If I can find out the name of the location, i'll add it later.
That round one that has the slatted walls, VERY KOOL.