Icehotel, Sweden
Credit: Stetson Freeman / The Christian Science Monitor / Getty Images

The first and the largest hotel of its kind, Sweden's Icehotel is redesigned and constructed anew each year, just outside the city of Kiruna. The hotel requires more than 30,000 tons of ice and snow to form the walls, floors, chairs, beds and pretty much everything else a guest might need. In this case "room temperature" means about 23 F, so guests are encouraged to dress appropriately in order to avoid becoming part of the decor.