Mineral Baths, Tokyo
Concierge.com's insider take:
Japan is famous for its rustic hot springs (onsen), and even Tokyo has its own mineral-rich baths. Azabu-Juban Onsen sits above a natural source whose dark waters are said to be good for all sorts of complaints, including poor circulation and sensitive skin (81-3-3404-2610; 1-5-22 Azabu-juban, Minato-ku; closed Tues). Soak in the old-style tiled baths and then relax with a beer and a plate of edamame soybeans. Alternatively, pay a visit to one of Tokyo's historic sento or public bathhouses. Built in the days when few houses had their own bathroom, their numbers are now sadly dwindling. One of the best is Daikokuyu, which has all the classic sento elements: spotlessly clean showers and baths for soaking (segregated for men and women) and giant murals of Mount Fuji (81-3-3881-3001; 32-6 Sento-kotobukicho, Adachi-ku). The etiquette is simple: Shower before getting into the bath, and once in the water, absolutely no soap, swimsuits, or washing of clothes!