

Ōtemaenochō, Japan
Spaworld,
Naked truth: Volcanically active Japan has thousands of natural hot springs traditionally enjoyed au naturel. One Osaka onsen has taken that concept to the extreme, creating an over-the-top, around-the-naked-world-in-eight-floors theme park. The complex is divided into themes by country—Finland, Greece, Spain, France, Ancient Rome, and so on. You'll soak amid a replica of the Trevi Fountain, in a hammam-meets-Disney stone bath, and over an Atlant...