Nakabusa Onsen: Day-Use Hot Spring Baths & Prices

In Azumino City at the foot of the Northern Alps, Nakabusa Onsen is a secluded spa welling up at about 1,460 meters elevation. Known also as a trailhead for Mount Tsubakuro and the Omote-Ginza ridge route, it has been beloved by mountaineers. Even by registered count it holds many source springs and boasts an abundant flow.

Highlights

A geothermal zone where steam rises from the ground spreads here, and you can enjoy natural steam baths and experiences using the earth's heat. The open-air baths beside the mountain stream are a luxurious time to feel the mountain air with your whole body. They carry the old atmosphere of taking the waters into the present.

Enjoying the Seasons

This is a seasonal inn, open roughly from spring through autumn. With fresh greenery in early summer, cool summer days, and crimson leaves in autumn, you soak while feeling the four seasons of the Northern Alps up close.

Access and Basic Information

It is about fifty minutes by car from Hotaka Station on the JR Oito Line, reached at the end of a climbing mountain road. During the climbing season, shared buses also run from stations such as Hotaka. It holds many source springs, most welling up very hot, and is known for source-fed water with no added water or heating. Day-use bathing is possible at a dedicated facility called Yuhara-no-yu, with adult admission around one thousand yen during limited daytime hours. Because both the inn and day-use bath operate seasonally, always check the open period and reception hours before you visit.

Practical Travel Notes

Nakabusa Onsen serves as a trailhead for Mount Tsubakuro and the Omote-Ginza traverse, and many visitors combine hiking with taking the waters. Even for a day-use bath alone, the mountain road must be driven both ways, so an unhurried schedule is reassuring. The recommended season runs from the fresh greenery of early summer to the crimson leaves of autumn, the only period it operates. Nearby are real peaks such as Mount Tsubakuro, the Kassen-one ridge trail, and Mount Ariake, and a bath after descending is exceptional. A day-use bath costs around one thousand yen, and staying overnight along with hiking lets you enjoy the quiet time unique to a secluded spa.

A Quick Tip

Owing to the high elevation, mornings and nights turn chilly. Many visitors combine it with hiking, so bring warm gear and comfortable walking shoes and keep your schedule unhurried. As it operates seasonally, it is important to confirm the open period and last reception time in advance.

Practical Information for Your Visit

• Spring quality: Simple sulphur spring (alkaline, hypotonic, high-temperature spring). It is colourless and transparent, with a pH of 8.7.
• Source temperature: The three sources feeding the day-use bath Yubara no Yu are Myoken no Yu at 94.8 degrees Celsius, Yakushi no Yu No. 1 at 94.6 degrees Celsius and Kojiki no Yu at 74.7 degrees Celsius. Across the inn as a whole, 29 sources are registered.
• How the water is handled: 100% free-flowing water straight from the source. There is no dilution, heating, circulation, colouring or chlorine disinfection. Every bath is drained, refilled and cleaned once a day. The very hot spring water is cooled to a comfortable temperature using water-cooled and air-cooled systems.
• Open-air baths: There is an open-air bath called Yubara no Yu reserved for day visitors. It is an open tub with no roof.
• Day-use bathing: Yubara no Yu is open 9:30-17:00 (last reception 16:00), and the bathing fee is 950 yen per person (including the 50 yen bathing tax).
• Day-use plans: As well as bathing alone, there are longer stay plans that include trying geothermal steam cooking, a tour of the grounds and a light meal.
• Season of operation: The main season runs from late April to early November. In 2026 the prefectural road opened at noon on 24 April, and day-use bathing began on 24 April with overnight stays from 27 April.
• Winter: From late December to early April the prefectural road is closed for the winter, so you cannot drive in. The winter opening held during this period involves a walk of about 4 hours.
• Parking: The car park closest to the trailhead for Mount Tsubakuro is a paid, reservation-only car park limited to 7 vehicles at 5,000 yen per vehicle. Reservations must be made at least two days in advance, arrival must be between 6:00 and 16:00, and payment is in cash.
• Access (by bus): From Hotaka Station on the JR Oito Line, take the scheduled Nanan Taxi bus bound for Nakabusa Onsen; the ride takes about 55 minutes and you get off at the terminus, Nakabusa Onsen (the Mount Tsubakuro trailhead). The service runs only from late April to early November, with extra early-morning departures at the height of the season. Elementary school children pay half the adult fare.
• Access (by car): From the Azumino side, follow Prefectural Route 327 (the Yarigatake-Yamura Line) to its end. It is a mountain road with long narrow stretches where passing oncoming vehicles is difficult.
• How long to allow: About an hour if you only bathe. However, since it is a round trip of about 55 minutes each way on mountain roads from Hotaka Station, it is safest to set aside half a day.
• Address: 7226 Hotaka Ariake, Azumino City, Nagano Prefecture
• Enquiries: 0263-77-1488
• Nearby: The Mount Tsubakuro trailhead, Ariakeso, Azumino and Daio Wasabi Farm

Information Sources

The spring quality, source temperatures, number of sources and the free-flowing policy, together with the reception hours and bathing fee of the day-use bath Yubara no Yu, the season of operation and the reservation conditions for the trailhead car park, are compiled from the hot spring guide, access guide and notices on the official Nakabusa Onsen website. The name of the spring type and the pH figure are taken from the hot spring information of the Nagano Prefecture Tourism Organization. The closure of the Nakabusa prefectural road in August 2026 was confirmed from the road closure information on the official Azumino City website (Crisis Management Division) and from reports by the Shinano Mainichi Shimbun and Nagano Broadcasting. The operating season of the shared bus and the handling of fares come from information provided by Nanan Taxi. Operating seasons, prices and road restrictions are subject to change, so please check the official information before you set out.