In the early 1990s, Horace Burgess started to build one of the largest tree houses in the world. The structure is over 100 feet tall and was completely built without blueprints over the span of about 15 years. If you’re around Crossville, TN you should check it out – The Minister’s Tree House is open to the public.

Photos from berlyjen, Chuck Sutherland, kristin_sweeting, and seduffel.