When I was 9 years old, my uncle hammered two slabs of plywood into a trio of apple tree branches in his backyard. I spent my tween years shepherding siblings and cousins on and off the shaky platform in an elaborate game in which I was always the captain — no surprise to friends — protecting them from harm. The tree house offered escape from the danger of marauders real and imagined, and it fueled our imaginations. What if we could eat, play, and even sleep in the tree?
Nearly three decades later equatorial Costa Rican sunlight seeps into my sleeping loft, nestled amid chilamate leaves 20 feet above the ground. A toucan has just passed by the deck of our stilted retreat, which abuts natural hot springs close to the Arenal Volcano some 60 miles north of San José. I descend to the main cabin, where Frances, my partner, heats water for coffee in a tiny, well-appointed kitchen. My childhood fantasies were never this good.
The latest trend in the travel world aims to help those who aspire to the ultimate vacation high, high up amid the trees in increasingly elaborate tree houses. Such arboreal abodes aren’t built just for your patchouli-wearing Julia Butterfly types anymore. (Remember her? The woman who lived in a redwood tree for two years?) These days jet-setting A-listers in search of adventure are traveling to the newly opened Ritz-Carlton Reserve in Puerto Rico or the Four Seasons Resort in Seychelles, where guests stay in tree house villas. Those with a high tolerance for adventure — and a high net worth — can travel as far as Ulsaba, Richard Branson’s private game reserve, where 11 “tree house-style” rooms offer panoramic views of jungle animals strolling by. Many boutique hotels, like the Uxua Casa Hotel & Spa in Bahia, Brazil, dreamed up by former Diesel creative director Wilbert Das, aim to up the “uniqueness” ante with a tree house — and some are elaborate; the Highland Haven Creekside Inn in Evergreen, Colo., offers a three-level structure complete with a bubble tub, a gas fireplace, and a flat-screen TV. Budget-conscious explorers, meanwhile, can find respite in one of the 221 tree houses listed on Airbnb, where “Trees & Zzzzs,” a collection of 32 lofty retreats from Illinois to India, has become one of the site’s most visited wish lists. That’s where, on a dreary morning last November, I stumbled upon a listing for “Rainforest Treehouse with Hot Springs ($85 per night).” Done.
So why has tree house tourism seen a spike in the past decade? For one, late ’90s engineering breakthroughs allow treetop structures more stability. As a result, there has been an explosion of creative designs by companies like Blue Forest, a U.K.-based builder of luxury tree houses formed by a pair of Kenyan brothers. These dwellings have been well documented in a half-dozen coffee table books (ogle their work at blueforest.com). As it does with most things, the Internet gets credit here too: Now that we can see all our friends’ vacation porn on Facebook (wow, did everyone I know stand in front of that same fountain in Berlin?), we’re all looking for something a little more original when we travel. And thanks to the rise of sites like TripAdvisor, Airbnb, and other travel startups, it’s much easier to discover new possibilities and connect to other people for advice.
Beyond that, tree houses capture our collective imagination. When a Swiss family en route to Australia was shipwrecked in the East Indies in the 1812 novel Swiss Family Robinson, they built their home in trees to survive. (Maybe you’ve seen the Disney World attraction.) The Berenstain Bears of the eponymous children’s book and television series lived in a tree. Only members of the “He-Man Woman Haters Club” were allowed inside The Little Rascals’ tree house. And who can forget Peter Pan’s Lost Boys, who in the film Hook lived in a tall tree on a rocky outcropping just off the coast of Neverland, where they slid down slides and through trapdoors and swung from branch to branch?
If you’re looking to capture that spirit, drive two hours northeast of New York City to Winvian, a collection of imaginative cottages nestled among lakes and forests on a 113-acre estate in tony Litchfield Hills, Conn. Commissioned by 15 architects, each to his whimsy, Winvian’s 18 dwellings include a refashioned 1968 helicopter and a maritime-themed cottage complete with a lighthouse, but among the most popular is the resort’s two-story tree house. To enter, visitors climb 35 feet up a modern staircase that traces the lines of the trees. There’s a Jacuzzi and a hot steam shower, but the collage of license plates framing the woodburning fireplace are meant to suggestw the Little Rascals themselves may have decorated this hideout, where prices start at $549 for a midweek overnight. (An all-inclusive fee of $1,050 a night will take care of all your meals and provide a fully stocked wet bar.) A pair of three-speed bikes with large baskets transport visitors around the grounds to hike, kayak, or tour the garden with chef Chris Eddy, who grows much of the food he prepares for the restaurant. Winvian also has a first-class spa, and massage therapists make (tree) house calls.
Across the pond the decadent English country resort Chewton Glen, a boutique hotel on the edge of New Forest National Park two hours southwest of London and frequented by the likes of Cate Blanchett, recently expanded its offerings to include a grove of tree house suites. Glide down the long drive past the formal 18th-century home (think Downton Abbey) and leave your car for a golf cart that will ferry you to the edge of a valley where a dozen suites are built into several buildings rising high above the valley floor. Visitors enter via gangplank to one of the dwellings, ranging in size from a studio, which starts at around $950 per night, to a full tree house, which runs upwards of $2,050 per night. Guests are free to explore the 130-acre property, from the golf course and spa to the Hampshire coast, but many opt to remain reclusive, partaking of the breakfast that arrives in a bright wooden hamper every morning.
The most recent convert to tree house tourism is Dorado Beach, a Ritz-Carlton Reserve resort and a restoration of a plantation Laurance Rockefeller bought in 1958. A-list vacationers back in the day included Ava Gardner and Presidents Dwight D. Eisenhower and John F. Kennedy before the hotel fell into disrepair. Individual rooms open onto the ocean and start at $1,499 a night, but the resort’s crowning feature is the Spa Botanico, which offers ancient Puerto Rican therapies delivered in, yes, open-air tree houses. Built from southern yellow pine nestled within a grove of indigenous black olive trees, these broad platforms offer a treatment area large enough for two to enjoy the signature tree house massage and a deck from which to enjoy the foliage.
Of course, tree house vacationing isn’t for everyone. For one thing, the fancy ones rarely come cheap. Unless you are willing to fork over more than $500 a night, your cottage probably won’t have a Jacuzzi, and you may have to put up with some creepy crawlies. You’ll also want to avoid the retreats if you’re afraid of heights — because of their stilt supports, many also sway a bit from the wind. And most are designed for people whose ideal vacation involves solitude.
That solitude, along with the proximity to nature, was exactly what Frances and I sought when we made our Airbnb reservation last fall. Kathy Dhyr, the proprietor of our tree house, wrote within a day with maps and notes on where to rent a car, what time to arrive, and how to arrange for the wife of a nearby farmer to cook our meals (chicken and rice dinner: $6). Kathy, an American nutritionist, writer, and community organizer, runs Bio Thermales with her German husband, Bernie, an engineer, gardener, and woodworker who built our tree house as well as the pools that are fed by the natural hot springs around the volcano.
We spent our days soaking in those pools and exploring the maze of hanging bridges in the nearby rain forests. Each evening we regrouped for beer and rummy in our arboreal retreat to the varying rhythm of the rustling leaves. Though the platform felt more sturdy, this tiny fort didn’t feel so different from the beloved playhouse of my youth. Next year I’m bringing my siblings and cousins.
This story is from the March 18, 2013 issue of Fortune.