World’s Coolest Tree-House Hotels

Why It’s Unique: Leading Swedish architects gave the backyard staple a strange futuristic makeover at the Treehotel outside Harads village (population: 600). Perched four to six meters above the ground, each of five treetop suites has its own look, whether resembling a bird’s nest, a flying saucer, or a construction of Lego blocks. The most ingenious suite has a mirrored exterior, reflecting the forest on all six sides.

Access: Ramp, bridge, or (if you’re lucky) electric stairs.

What to Do: Pursue the Northern Lights by dog-sled ride or snowshoe hike through the Lule River Vally in winter, or go fishing and kayaking in summer.

—Adam McCulloch