Getaways with sauna

Allgäu, Bavaria

Ten wood igloo-shaped tiny houses sit on a swimming lake at Campingplatz Röhrenmoos near Wangen im Allgäu, with sauna and kitchen included.

Big Island, Hawaii

A one-bedroom treehouse on a 3-acre fruit farm in the Kaloko rainforest near Kailua-Kona, Hawaii, with ocean views, a hot tub and sauna.

Olympic Peninsula, Washington

A 20-foot-high treehouse over the water near Port Angeles, Washington, with two bedrooms, a hot tub and sauna, sleeping two.