Leave it to the Swedes to build the Treehotel, wildly designed tree houses deep in the woods, about an hour from the small town of Lulea and just less than 40 miles from the Arctic Circle. These aren’t your typical tree houses, either. One, the Mirrorcube, is lined on the outside with mirrored glass allowing the entire tree house to fade into the woodsy backdrop. Then, there’s the Bird’s Nest. The outside is made to look like a bird’s nest made of branches, while the inside is a sleek and modern room and bathroom. The hotel’s rooms are accessible only by retractable staircases.