1 Treehouse Mahal

Constructing a treehouse in the image and likeness of the Taj Mahal, one of the Seven Wonders of the World, is by no means a simple venture. John Lionheart of Berkeley, Calif., used a jigsaw to fashion plywood into ornate trim, emulating the embellishments of the actual mausoleum in Agra, India. The treehouse is structurally comprised of laminated redwood joist and beams and features a winding staircase, brass fireman's pole, rope climb and a captivating view of the Golden Gate Bridge.

Although the 60-year-old magnolia tree offers spring blooms and a beautiful view, its dense trunk-to-limb structure demanded a bit of engineering prowess. "It was a tricky build because the treehouse had to be offset inside [the tree]," Lionheart says. To balance the house's weight, he used a custom-made Simpson T-bracket to clamp the main horizontal support beam to the tree without penetrating it.

Lionheart advises avoiding this scenario altogether. "I recommend looking for a tree with a strong central crotch where you can balance a beam to serve as the backbone of the structure," he says. Despite these structural pitfalls, the Taj Mahal treehouse is a splendid tribute to the historical monument.