Tenku Spa Hills Ryusenji no Yu is the Moriyama flagship of a chain that calls itself the birthplace of the super sento and of high-concentration carbonated baths, open on this site since 1989. Its natural alkaline hot spring feeds open-air baths with a view. Saunas are a 'bazooka' löyly sauna with löyly on the hour and half hour, an outdoor self-löyly meditation sauna for men and a salt sauna for women, with cold baths below 10°C. Open 6:00 to 2:30 daily; entry ¥850 on weekdays.