Ganban'yoku

A ganban'yoku is a hot stone spa originating in Thailand that has become popular in Japan. Body-sized stones, such as granite, are inseted into the floor and heated; users lie, clothed, on the stones, their bodies gradually heating up. Many onsen, including Spa LaQua at Tokyo Dome City, have ganban'yoku rooms. Like low temperature saunas, ganban'yoku are said to have a detoxification effect, improve the circulatory system and are good for the skin. A ganban'yoku room in a spa would typically be visited after the baths and would be in a clothing-on area with mixed genders.