Getaways with sauna

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.

Santa Teresa, Puntarenas

A 13-bedroom treehouse retreat near Playa Hermosa in Santa Teresa, Costa Rica, built around a large sauna and jungle lookout decks.