Scientists believe that early human ancestors, like most great ape species, dwelled in trees. More recently in human history, treehouses became popular in the Roman era and then later in the Renaissance, when the wealthy Medici family constructed them in the gardens of their villas in the Tuscan countryside. And in the mid-19th century, a Parisian suburb called Le Plessis-Robinson drew fashionable city dwellers to its chestnut-tree bars and restaurants, where roast chicken and champagne would be carried up to diners on rope pulley systems.

Today, treehouses are still common in regions of Asia with seasonal flooding, and the Korowai people in Papua, Indonesia, continue to live in treehouses to avoid capture by rival clans. In Western culture, new building technologies, a growing interest in the use of environmentally sustainable materials, and a desire to escape city life and retreat into nature have fueled a resurgence of interest in treehouses in recent years. (The most wished-for listing on Airbnb worldwide is a treehouse located in the heart of Atlanta. The house is divided into three distinct areas—“Mind,” a sitting room for reading and relaxing; “Body,” a bedroom that sleeps two; and “Spirit,” a hammock deck surrounding a 165-year-old pine tree.)

Below are eight of the most fascinating modern treehouses around the world, designed by leading architectural studios; small, eco-forward firms specializing in treehouses; and free spirits in search of an off-the-grid lifestyle. Some are private residences, while others are hotels or educational centers welcoming the most adventurous of nature fanatics.

In 2011, Foster Huntington, an up-and-coming menswear designer living in New York, purchased an ’87 Volkswagen Vanagon, quit his office job, and drove across the United States, documenting his off-the-grid lifestyle on social media and his popular blog, “A Restless Transplant.” Eventually, he settled in southern Washington, where he and his friends constructed a treehouse on a hilltop overlooking the Columbia River Gorge. Named the Cinder Cone for its location on an old volcano site, the treehouse-complex consists of two structures—the Studio and the Octagon—which are connected by a rope bridge. On the ground level, a large concrete skate bowl offers yet another outdoor adventure. “I could’ve bought a house,” Huntington told the New York Times in 2015. “But this is so much better. For me, it’s realizing a childhood dream.”

Norwegian interdisciplinary design firm has tackled projects as far-ranging as reindeer observatories, museums, and fish markets. In 2017, they revealed the 7th Room, a new addition to the Treehotel—a magical treehouse resort in the remote pine forests of Northern Sweden, and a bucket-list item for both design and nature seekers.

Supported by 12 columns, the nearly 500-square-foot Nordic cabin is perched, seemingly weightlessly, around 32 feet above ground. The architects sought to blur the boundaries between shelter and nature: on the cabin’s bottom surface, a trompe-l’oeil black-and-white print of the forest allows the structure to virtually disappear into its surroundings. Up above, large windows offer 360-degree views of the Lapland forest and the Lule River, and a netted terrace that connects the two bedrooms provides an ideal spot for stargazing.

Former software developer Joel Allen was inspired to begin a new career in carpentry when he befriended a free-spirited elderly carpenter at a garlic festival in 2008. After picking up basic woodworking skills, he had the idea to build an egg-shaped treehouse in the backwoods of Whistler, where he was based, and found the perfect location in a mossy outcrop overlooking a stand of old-growth hemlock trees. After installing the foundation, Allen finished his “HemLoft” with second-hand materials, including wooden doors, glass sheets, and lumber—all scored for free off of Craigslist.

Tham & Videgård’s Mirrorcube (2008–10) is another fascinating, and almost imperceptible, dwelling at Sweden’s Treehotel. The aluminum structure is covered in mirrored glass that reflects the blue skies and pine trees of its surroundings. Inside the small cube—measuring roughly 13 feet on each side—a minimal, hygge interior offers a double bed, living room, bathroom, and roof terrace. The glass exterior is laminated with a transparent ultraviolet color that is visible only to birds (so that they don’t collide into the structure). According to the architects, Mirrorcube represents the inherently challenging relationship between man and nature, and the need for high-tech materials and equipment in order to experience remote places with harsh climates.

Located in a small valley in Lower Saxony, this treehouse was designed by baumraum, a German firm that specializes in treehouses, for a family seeking a playful haven for their young son and their friends. The idyllic site includes a small brook and two large ponds. A long terrace connects several sturdy hemlock spruce trees with the treehouse, which is perched above the pond. Inside the arched two-story structure, an upper bedroom with a domed skylight provides an expansive view of the night sky. During the day, the terrace serves as a perfect observation point for spotting creatures in the water and the surrounding forest.

Architect and architectural historian Fujimori is best known for his towering, whimsical tree houses; he once said that “a building should not resemble anyone else’s buildings, past or present, or any style that has developed since the Bronze Age.” Nestled among cherry blossoms in the Kiyoharu Art Village—an arts complex including galleries, a ceramic studio, library, and chapel—the minimal yet fantastical Teahouse Tetsu (2009) rests roughly 13 feet above ground on a single 80-year-old cypress trunk. Between museum excursions, visitors can take a break to admire the structure and its surrounding scenery, or climb up the ladder and enter the house for an open view of the park.

Immersed in West Virginia’s woodsy Summit Bechtel Reserve, the Sustainability Treehouse (2013) was designed by integrated design firm Mithun for the Boy Scouts of America and functions today as an educational facility for the study of ecology and resource conservation. The treehouse itself is a shining example of environmental leadership: Its vertical, multi-story design minimizes disturbance to the forest, local timber was used to build the structure, and it’s a net-zero energy, net-zero water facility, thanks to a rainwater recovery system and both wind- and solar-generated energy. On its indoor and outdoor platforms, visitors can learn about the surrounding site and ecosystem, as well as sustainable design, through interactive exhibits and galleries.

Rebelo de Andrade Studio sought to “recreate the fantasy of tree houses” for Pedras Salgadas Park, an upscale retreat in northern Portugal. Long, narrow, and angular, the resulting Tree Snake Houses (2013) were constructed of raw materials, like slate and wood on their exterior, to create the impression of a wild snake gliding through the woods. Sustainability was central to the treehouses’ design, with features including water reuse, water solar panels, and low-consumption LED technology. The studio is currently developing more models of the houses for other terrains, like the Mountain Snake House, the River Snake House, and the Sand Snake House.