This "egg in a tree" hidden on crown land in the woods of Whistler, Canada is called The HemLoft. Built by Joel Allen and his fiancée Heidi using mostly free materials (including $10,000 worth of scraps scored from Craigslist), The HemLoft was secret until it was revealed to the world in Dwell Magazine. In 2013, Allen announced that he'd be posting the HemLoft's materials as a "disassembled DIY package" for someone else to use in Whistler's free section of Craigslist, making the project come full circle.
For Kids: Shanty Treehouse
This crooked Shanty Treehouse from North London's High Life Treehouses Ltd. has a playful, storybook look (not unlike the Berenstain Bears treehouse). While the firm also makes "hobbit holes," wooden play structures and treehouses for adults, this two-level treehouse is the perfect escape for kids.
For Adults: Greenwood Home
Architect Charles Greenwood of Greenwood Engineering built his 700-square-foot treehouse home in 2006. With years of know-how from building treehouses for others under his belt, he added thoughtful and structurally-sound details like support poles and flexible joints to compensate for the natural motion of the trees in the wind.
For Kids: Cedar-Shake Treehouse
This Oakland, Calif. treehouse by Nelson Chan of 2Chan Design is the turf of a 6-year-old named Loula, but its wraparound deck, built-in bench and skylights make it a favorite spot for adults to hang out, too.
For Adults: Brooklyn Treehouse
Built behind artist Alexandra Meyn's Brooklyn apartment, this eye-catching treehouse only cost $400, though you'd never know by its appearance. The structure is more sophisticated than your average childhood fort (French doors!), but still has an air of youthful whimsy about it with the eclectic furnishings. And though it's in an urban space, the worn wood and mulberry tree foliage lend it a natural rusticity.
For Kids: Captain Jack's Flying Pirate Ship
Sailing 10 feet above ground, this pirate ship by John Carberry of Peacemaker Treehouses has everything a little seafarer could want: a cabin, masts, gun ports and a rope ladder.
For Everyone: Majestree "Treesort"
The Majestree is part of Michael Garnier's family of treehouses that he runs as a bed & breakfast or "treesort," if you will. At 47 feet high, it's the tallest of the residences and can accommodate up to six people with a full bathroom and kitchenette to boot. The Douglas fir running right through the middle of it is very dramatic, but be warned: The Majestree is closed during wind storms.