Well I couldn't find one , if we have one :-/ :-/. So here's a interesting tree house I saw lately. Didn't build it , just on the way to the job site and thought it was worth a photo. Base is a old Fir stump, I think, althought all I've done is a drive by on it. The living tree is a Madrona.
(https://i21.photobucket.com/albums/b299/PEG688/Aug28th1.jpg)
(https://i21.photobucket.com/albums/b299/PEG688/Aug28th.jpg)
Here's a little about the Madrona tree, very odd tree, really.
http://seattletimes.nwsource.com/html/outdoors/2002049584_nwwmadrona30.html
http://en.wikipedia.org/wiki/Madrone
Interesting, PEG. I have a tree that would like a treehouse -- it's tempting but the tree is so nice I don't want to put one in it. Maybe some day I'll find another tree.