What) In the early 1990s, landscaper Horace Burgess bought some wooded land on the outskirts of Crossville. One of the bigger trees, next to a dirt road, caught his eye. He decided to build the world's largest tree house in its branches. But Horace had a job and a family. After spending a couple of years on the project, he ran out of lumber and enthusiasm. "Then I turned my life over to God," Horace recalled. "And the spirit of God said, 'If you build Me a tree house, I'll never let you run out of material."
Horace got himself ordained as a minister and went back to work. God showed Horace what the tree house would look like ("It was like a vision") but didn't tell Horace how big it would be. "If He had," Horace said, "I would've tried to talk Him out of it." Eleven years of labor and $12,000 later, Horace had what he'd originally wanted: the largest tree house in the world. It spreads across not one, but seven big trees that grow through its floors and out of its windows. It soars 100 feet into the sky. Built without blueprints, its dimensions are a mystery even to Horace, who guesses that it covers around 10,000 square feet.
News of Horace's project spread quickly among local churches. Even before he was finished, people began showing up to climb it. They were trespassing then, and they're trespassing now, but Horace has never had the heart to turn them away. Thousands of uninvited people have visited the tree house over the years, with God as their only lifeguard. "I built it for God, and God watches over it," Horace said. "He's protected everyone for all these years."
Horace
plans to build a Welcome Booth where all visitors will sign
waivers so that they no longer have to trespass. The
long-delayed Phase 2 of the tree house will include an
elevator, power, plumbing, heat in the winter, and a
fitness-testing "Stairway to Heaven" that will twist all the
way up to the belfry. "It's only started, really," Horace said
of the tree house. "I want to go back and finish what it looks
like in my head." (1)
Where) Beehive Lane I-40 exit 320. Turn north onto Hwy 298, then make an immediate right at the stoplight onto Cook Road Drive. As the road takes a sharp right, instead make a sharp left onto Beehive Lane. Drive about a half-mile. The pavement will end, but keep driving.
Why) When
it comes to Buckys like this the key question seems to be “Am
I willing to trespass to see the good stuff?” As I am
coming to discover, the answer is almost always no. 
... this is the second one. Do the warnings on these gates seem to be serious about keeping people out of the tree house?
