A Hot Spring Pool of 1923
Nakabusa Onsen Large Hot Spring Pool (中房温泉温泉大プール, Nakabusa Onsen Onsen Dai-Puru) is an outdoor stone pool built in 1923 at Nakabusa Onsen in Hodaka Ariake, Azumino City, Nagano Prefecture, registered as a Registered Tangible Cultural Property on 25 July 2011. It carries registration number 20-0376 and is the only one of the seven registered at the spa as a structure other than a building, counted as one site.
It lies at the southwest of the spa and is filled with hot spring water rather than cold. It measures 8.7 metres wide and 17 metres long, with a depth of 1.2 metres and an area of 147 square metres.
By the Taisho era Nakabusa was a summer retreat as well as a base for climbers. In 1918 the educator Sawayanagi Masataro of the Seijo school held a forest school here. Hoyano Shigeo of Shinshu University points to the pool as evidence of that growth into a resort shaped by its natural setting, and the Agency for Cultural Affairs calls it a pioneering facility of the modern hot spring resort.
Walls of Ariake Granite
The walls are built of cut blocks of Ariake granite, quarried in the surrounding area and laid in four courses. On the north, west and east sides, steps of two courses lead down into the water.
The builders did not haul material from far away; they built the pool out of the rock underfoot. The Nakabusa valley is granite country, and the spring water itself rises through fractures in that granite. You bathe in hot water held by the same stone it came through.
It was registered for its contribution to the historic landscape. The only Taisho-era property of the seven, it shows more clearly than any other how the spa widened from a place of cure into a place of leisure.
Using the Pool
The Nakabusa Onsen Large Hot Spring Pool is still in use. According to the inn, it is filled each year between June and mid-October, and bathers wade through it for a walking bath. Swimwear is required.
When it is full, the pale granite walls and steps run down beneath the water. When it is empty, the four courses of stone and the steps on three sides stand fully exposed, which makes the construction even easier to read.
Seeing the Pool
The Nakabusa Onsen Large Hot Spring Pool lies inside a working inn, and bathing in it or viewing it is limited to overnight guests and to those booking a day plan that includes a walk through the grounds with the registered buildings. Conditions change with the season, so check when you book.
This is a bathing facility: if you take photographs, make sure no other bathers appear in them. Season and transport details are on the Nakabusa Onsen page.
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Q&A
- When was Nakabusa Onsen Large Hot Spring Pool built?
- In 1923, according to the Agency for Cultural Affairs.
- Can visitors bathe in Nakabusa Onsen Large Hot Spring Pool?
- It is filled with hot spring water between June and mid-October and used for walking baths. Swimwear is required, and use is limited to overnight guests and day-plan users.
- How large is Nakabusa Onsen Large Hot Spring Pool?
- It is 8.7 metres wide, 17 metres long and 1.2 metres deep, with an area of 147 square metres.
- What is Nakabusa Onsen Large Hot Spring Pool made of?
- Cut blocks of local Ariake granite laid in four courses, with two-course steps on the north, west and east sides.
- Why is Nakabusa Onsen Large Hot Spring Pool a Registered Tangible Cultural Property?
- It was registered for its contribution to the historic landscape. The Agency for Cultural Affairs regards it as a pioneering facility of the modern hot spring resort.
Basic Information
| Name | Nakabusa Onsen Large Hot Spring Pool (中房温泉温泉大プール) |
|---|---|
| Location | 7226 Hodaka Ariake and other lots, Azumino City, Nagano Prefecture |
| Designation | Registered Tangible Cultural Property (structure), registration number 20-0376 |
| Year Designated | Registered 2011/07/25 (Heisei 23) |
| Quantity | 1 site |
| Dimensions | Stone construction, area 147 sq m, 8.7 m wide, 17 m long, 1.2 m deep |
| Owner | Nakabusa Onsen Co., Ltd. |
| Public Access | Used and viewed by overnight guests and day-plan users; filled with hot spring water in summer and autumn only |
References
- National Cultural Properties Database, Agency for Cultural Affairs: Nakabusa Onsen Large Hot Spring Pool
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00008689
- Cultural Heritage Online: Nakabusa Onsen Large Hot Spring Pool
- https://online.bunka.go.jp/heritages/detail/233150
- Hoyano Shigeo, essay on the mountain culture of Nakabusa Onsen (Nakabusa Onsen website)
- https://nakabusa.com/pdf/historyandnature_03.pdf
- Nakabusa Onsen official website (baths, history, day plans)
- https://nakabusa.com/
- Nakabusa Onsen official English page
- https://select-type.com/s/nakabusa-english
Last verified: 2026.09.25
