Anthropologists believe our ancient human ancestors spent their time in trees, so it should be no surprise we love treehouses today.
Treehouses of all kinds are experiencing a renaissance.
When an acre-size slice of land in Gold Hill, Colorado, came on the market earlier this year, local resident Jessica Brookhart, 41, snapped it up for $80,000.
The draw for her: The house was a treehouse.
It was a place she could hang out with her husband and two young boys.
"I had never been inside it, but had admired it from a distance," she said, admitting it was an emotional purchase.
The man who owned the land had built the treehouse with materials from a recycling center in neighboring Boulder. The structure can fit two adults and two children. There's no bathroom or running water, and a squat potty is outside down on the ground. There's a camping stove for cooking, and water has to be brought up. From the windows, you can see Longs Peak and the Continental Divide.
"Since I was a little girl, I was obsessed with little mini-houses, or sheds and treehouses," Brookhart said.
She sometimes rents the treehouse out online, and to her surprise, lots of people want to use it.
"For me, it's this magical place," she said. "I have to block off a bunch of weekends just so we can spend time there too."
Treehouses have proliferated during the pandemic. There are stylish backyard ones built by professionals, and makeshift ones thrown up just to escape the four walls of home. There are listings on sites like Airbnb for treehouses to camp in.
Unlike the rickety treehouses of yore, many of these new ones have been upgraded. Most are still accessed with a ladder, however, requiring you to climb.
As pandemic lockdowns droned on, Nanci and Ethan Butler of Newton, Massachusetts, decided to build a backyard treehouse for their two kids. Ethan, an engineer, found treehouse floor plans online and modified them to accommodate their family.
Building the house was a family affair, and in about three months, the Butlers had a beautiful hideaway with built-in bunk beds and a front deck. They enjoyed some nights camping out in it.
Then, on a serene day about three weeks after it was finished, a big oak in the yard broke in two. Part of it fell directly onto the treehouse, crushing it. Carpenter ants had brought the tree down.
"It was traumatic, I was stunned," Nanci, 45, said. "But we were also so saturated with despair at that point. Nobody cried."
More people have been drawn outdoors and into nature during COVID, and treehouses are part of that pattern, said Jeff Galak, associate professor of marketing at Carnegie Mellon University's Tepper School of Business.
"They are an attempt to do something fun and interesting and away from other people," Galak said.
Part of treehouses' popularity, he said, is parents' desire to create more backyard amenities so kids will go outside.
Nostalgia is another part of it.
"Nostalgia is a huge driver for consumers in general," he said. "People are being creative with how they engage with that type of nostalgia."