A few more images, via Google, to put the earlier comments in perspective. Primary docs are the truth. In this age of Google, there's no reason for us to rely--strictly--on interpreters. We have the tools to consider history for ourselves. There is no need to be blinded by Lost Causers the answers are at our finger-tips. To quote Public Enemy, "Some devils prevent this from being known\But you check out the books they own..."
A treehouse can be an ideal office space, vacation rental, and way of reconnecting with your youth.