A Working Powerhouse Since 1928
The Heisakubara Power Station Main Building (平作原発電所本館) is a two-storey reinforced concrete powerhouse built in 1928 in Kamisaibara, Kagamino Town, Okayama Prefecture, and registered as a Registered Tangible Cultural Property on 29 November 2006.
It has a building area of 338 square metres, and the registration includes its tailrace. The building stands about 330 metres below the head tank on the hillside; water dropped through the penstock spins the turbines here and then returns to the river through the tailrace.
According to Chugoku Electric, the station started in February 1928 with 1,800 kilowatts and was upgraded to 2,900 kilowatts in 1930. It still generates power today, with no staff on site; it is operated remotely from the company's Tsuyama control office.
Two Blocks, Two Jobs
The Heisakubara Power Station Main Building was registered as a structure that contributes to the historic scenery of the country. The Agency for Cultural Affairs describes its exterior as true to its function, the look of a piece of infrastructure.
It is made of two joined blocks. The larger, a gable-roofed hall 12 metres by 14 metres, houses the generators and the switchboard room. Attached to it is a flat-roofed block holding the switchgear room and a former transformer room, with tall, narrow windows along its north wall.
Each block takes the roof and shape that suit its job, and the two sit side by side without ornament. What the building does is exactly what it looks like.
For a small mountain hydro plant of the early Showa era, it is a clearly documented example of the then-new reinforced concrete construction.
What to Look For
Pick out the two blocks from outside: the big gabled hall and the flat-roofed wing. The tall windows on the wing's north wall, which light the switchgear and transformer rooms, give the building its most distinctive face.
Granite retaining walls laid in the Tanizumi pattern bend around the west and north sides of the building. They are registered too, and they are what created level ground for the powerhouse in this narrow valley.
The penstock comes down the slope beside the building. This is the only spot among the ten registered structures where tank, penstock, powerhouse and retaining walls can all be taken in together.
Visiting the Main Building
The Heisakubara Power Station Main Building is an operating power station, and its interior is not open to the public. Chugoku Electric says the exterior can be viewed at any time, but the grounds and any gated or fenced area are closed, so you will be looking from places where access is permitted.
The address is Heisakubara 1878, Kamisaibara. Chugoku Electric gives about 70 minutes by car via the Innoshō Interchange on the Chūgoku Expressway and about 75 minutes by car via JR Innoshō Station on the Kishin Line. Deep snow covers the area in winter.
There is no fee. The company's page gives no restriction on photographing the exterior, but operational areas cannot be entered for pictures.
- 📍 Plan Your Visit to Okayama
- Find tours, activities & transport passes near Heisakubara Power Station Main Building
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Q&A
- What is the Heisakubara Power Station Main Building?
- It is the two-storey reinforced concrete powerhouse of Heisakubara Power Station, built in 1928. It has a building area of 338 square metres and a tailrace, and became a Registered Tangible Cultural Property in 2006.
- Is the Heisakubara Power Station Main Building still in use?
- Yes. It is an operating power station with no staff on site, run remotely from Chugoku Electric's Tsuyama control office.
- What are the architectural features of the Heisakubara Power Station Main Building?
- A gable-roofed hall of 12 by 14 metres for the generators and switchboard is joined to a flat-roofed block for switchgear and a former transformer room, with tall windows on its north wall.
- Can I go inside the Heisakubara Power Station Main Building?
- No, the interior is closed. The exterior can be viewed at any time free of charge, but the grounds are off limits.
- How do I get to the Heisakubara Power Station Main Building?
- The address is Heisakubara 1878, Kamisaibara, Kagamino Town, Okayama Prefecture. It is about 70 minutes by car from the Innoshō Interchange, or about 75 minutes by car from JR Innoshō Station.
Basic Information
| Name | Heisakubara Power Station Main Building |
|---|---|
| Location | Heisakubara 1878, Kamisaibara, Kagamino Town, Tomata District, Okayama Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2006/11/29 (Heisei 18) |
| Quantity | 1 building |
| Dimensions | Reinforced concrete, 2 storeys, building area 338 square metres (with tailrace) |
| Owner | Chugoku Electric Power Co., Inc. |
| Public Access | Exterior viewing only; interior and grounds closed |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Heisakubara Power Station Main Building
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00006051
- Cultural Heritage Online: Heisakubara Power Station Main Building (Japanese)
- https://bunka.nii.ac.jp/heritages/detail/182266
- Agency for Cultural Affairs, Database of National Cultural Properties: Heisakubara Power Station Penstock and Main Building Retaining Walls
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00006052
- Chugoku Electric Power: History of Heisakubara Power Station (Japanese)
- https://www.energia.co.jp/isan/heisakubara_history.html
- Chugoku Electric Power: Heisakubara Power Station, Historic Electric Power Heritage (Japanese)
- https://www.energia.co.jp/isan/heisakubara.html
- Kagamino Town Tourism: Lake Onbara (Japanese)
- https://www.kagamino.holiday/spot/entry-322.html
Last verified: 2026.09.25
