Nagano Minamiminowa Village
Enjoy an exceptional open-air forest bath surrounded by red pines and an authentic sauna.
"Fureai Koryu Center Oshiba no Yu" is a day-use hot spring facility located within the vast Shinshu Oshiba Kogen in Minamiminowa Village, Nagano Prefecture. It is easily accessible, about 5 minutes by car from Ina IC, yet its greatest appeal is the outstanding quiet and natural setting surrounded by a rich forest of red pines. The water is a gentle alkaline simple hot spring with a pleasant feel on the skin. The indoor bath features a low-temperature Gengen Milky Bath (lying bath) where you can soak for a long time, while the open-air area offers rock baths and jacuzzis where you can enjoy the feeling of forest bathing. It also has a spacious sauna, one of the largest in the region, with seating for about 20 people, as well as a cold plunge bath filled to the brim with cool underground water, allowing you to fully refresh both body and mind.
A mildly alkaline simple hot spring with a pH of 8.0. The water is clear, colorless, and very gentle. The open-air bath is surrounded by a red pine forest, offering a superb forest-bathing experience as you listen to birdsong and take in the fresh negative ions. The indoor bath includes a lukewarm Genzen Milky Bath (lying bath), where you can take your time and enjoy a deep, relaxing soak.
A spacious sauna room with two tiers and seating for about 20 people, making it one of the largest in the region. Large windows let you relax while looking out at the green forest, adding to the feeling of openness. Regular events featuring guest heat masters and löyly / aufguss are also held, making this a fully authentic sweating space much loved by sauna enthusiasts.
A large cold plunge bath located just outside the sauna room. It uses high-quality underground water from the Ina Valley, and the water feels very gentle and smooth on the skin. The temperature is not too cold, and its wonderfully mellow quality, like being wrapped in a protective layer, soothes your overheated body after the sauna.
[Day-use bathing] 10:00-21:30 (last admission 21:00) *Closed every Thursday. *Due to renovation work, the facility is scheduled to be temporarily closed for a long period from July 16, 2026 (Thu) to January 31, 2027 (Sun).
Nagano
A celebrated spot with drinkable North Alps groundwater and the nation’s top electric baths
Nagano
A premium Karuizawa resort where you can totonou in a natural hot spring with water flowing directly from the source and the forest’s spring water
Nagano
A highland hot spring resort standing by Lake Shirakaba
JAPAN'S FINEST ONSEN & SAUNA
The Finest Onsen & Sauna in Japan
61 SELECTIONS
Most of what we surveyed never even made it onto this site. This book is a further cut from what did. Our editor bathed in every onsen and sauna in it, and wrote only what they confirmed on the ground.
