It seems like nearly every new urban hotel in Europe is sustainably built and at least moderately planet-friendly. But the Old World isn鈥檛 exactly a hotbed for eco-tourism the way tropical destinations in Central America and Southeast Asia are. So bona fide back-to-the-Earth eco-lodges like these three are hard to find.
The Best European Eco-Lodges: Treehotel, Sweden

Hidden in the woods of northern Sweden sit the five treehouses that make up . Each structure is unique, from the Mirrorcube (a 12-foot by 12-foot box with exterior walls of mirrored glass) and the silver flying-saucer-shaped UFO to the aptly-named Birdsnest and the bridge-accessed cabin. All are built on live trees with hardly any physical impact to the landscape, and are equipped with LED lighting and combustion toilets. Rooms are no bargain, though: rates start at close to $400 a night.
The Best European Eco-Lodges: Whitepod, Switzerland

Open only in winter, takes a little of the guilt out of the high impact of lift-served alpine skiing. The lodge consists of 15 geodesic-dome-shaped white canvas tents atop wooden platforms clustered around a two-century-old farmhouse on a mountain slope at roughly 5,000 feet of elevation in the Swiss Alps. Each lantern-lit dome is heated comfortably with a wood stove, and the interiors are the ultimate in backwoods luxe, down to the high thread count linens. The resort is less than a half hour from Les Portes du Soleil ski area, but it also boasts its own private ski runs with three lifts. You can also go dogsledding, snowshoeing, and Nordic skiing from the property. Rates start at $250 a night.
The Best European Eco-Lodges: Instants d’Absolu, France
Built on the edge of a nature reserve in the high alpine plains of the Auvergne region, about five hours south of Paris, sits restored into a Euro chic eco-lodge. Use it as a well-appointed base camp for mountain biking, fishing, and hiking in the Auvergne Volcano National Park and, in the winter, cross-country skiing. Rates start at about $130 a night.