Thanks to Architectural Digest for this:
The sauna has long been a structure for major events—from religious ceremonies to the healing of illnesses—and of course for socialization. For many cultures, the sauna is essential to well-being. It’s where the body is afforded the ability to relax and the mind can open new channels of thought. Some cultures and countries, however, are more reliant on saunas than others. In Finland, for example, there are more than 3 million saunas for its 5.5 million residents. Whether they’re in Finland or in any other neighboring Nordic country (where saunas are also prevalent), these structures are traditionally made of wood with a basket of rocks inside that’s heated by a stove. But it’s the exterior where the design can shine and where one sauna can distinguish itself from all others. From mobile structures that float calmly on lakes to a sauna that’s dressed as a big golden egg, find nine of the world’s most beautiful outdoor saunas below.