This is one of the most luxurious and ambitious bathhouses I've seen. Accommodating up to 5,000 people, it draws upon hot springs 890m (2,970 ft.) below the earth's surface. On its roof, in a large hangarlike room, is a covered swimming complex that includes a pool, various water slides, a kids' pool with aquatic activities, and a sunning terrace with Jacuzzi. You wear your swimming suits here (rental suits available). For a more grown-up experience, the rest of the large complex is divided into themed, geographical bathing zones, which are rotated between the sexes (no suits allowed) and include luxurious locker rooms. At the Asian Zone, for example, Middle Eastern music and tiled mosaics set the tone for the Turkish bath, while China is represented by a medicinal bath. Massage, sauna, mud baths, and hot stone and moxibustion treatments are available. If you're timid about going to a public bath, this one will convert you. If you're already a fan, you'll want to move in. But sorry, people with tattoos -- associated with the Japanese mafia -- aren't allowed.