Located in Crossville, Tennessee, the Minister's House took Horace Burgess 14 years to build around an 80-foot-tall white oak tree, with a diameter of 12 feet. The wooden edifice itself is 97-feet-tall and it's supported by six other strong trees that act like natural pillars.

Burgess says he started working on this giant treehouse after he had a vision back in 1993. God spoke to him and said: "If you build me a

treehouse, I'll see you never run out of material." And so he spent the next 14 years building God's treehouse, using only salvaged materials, like pieces of lumber from garages, storage sheds and barns. So, as far as Horace is concerned, God did provide him with all the materials he needed.

Although he never bothered to measure Minister's House (he estimates it must be about 8,000 to 10,000 square feet), he did count the nails he had to hammer into it, 258,000. It cost the 56-year-old landscape architect around $12,000 to construct the world's biggest treehouse.