The Main Building and Tailrace Power Station
The main building and tailrace power station of the Former Yaotsu Power Plant Facilities (旧八百津発電所施設) stand on the right bank of the Kiso River in Yaotsu, Yaotsu Town, Kamo District, Gifu Prefecture, and this hydroelectric plant of 1911 was designated an Important Cultural Property in 1998 (Agency for Cultural Affairs).
The Agency records the main building as a generator hall, a transmission hall and a discharge channel, and the tailrace power station as a powerhouse with its own small tank. Its designation number is 02346; the head tank and spillway on the hill were later added to the same designation of the Former Yaotsu Power Plant Facilities.
Brick Halls for Generators and Transmission
The generator hall is brick, with a building area of 826.0 square meters and a copper roof, and its three generating units and one travelling crane are included in the designation (Agency for Cultural Affairs). The machines that made electricity here from 1911 until the plant closed in 1974 (Yaotsu Town) are part of the protected property.
The transmission hall is a two-storey brick building of 475.5 square meters with a copper roof; it includes five sets of penstock channels, though the steel pipes themselves are gone (Agency for Cultural Affairs). The concrete discharge channel returned the used water to the river.
Yaotsu Town describes the mortar-rendered brick exterior as carrying traces of European architecture.
Why It Is an Important Cultural Property
The Agency designated the main building and tailrace power station of the Former Yaotsu Power Plant Facilities as both technically outstanding and of high historic value.
They belong to the first power plant on the Kiso River system and to the earliest generation of Japanese plants built to send large amounts of high-voltage electricity to cities. With generators and cranes still in place, the halls show how the plant worked, not only how it looked.
The Tailrace Power Station
The tailrace power station reused the drop of water leaving the main building to generate more power. The Agency's commentary says it was built northwest of the main building in 1917, while the date field in the same database gives 1911, the year of the main building; the two records disagree.
Its brick powerhouse covers 83.2 square meters and holds one generating unit and one travelling crane, and its reinforced-concrete tank covers 80.7 square meters (Agency for Cultural Affairs).
What to Look For
From outside, the main building of the Former Yaotsu Power Plant Facilities reads as a long brick block facing the river. Compare the height and window rhythm of the generator hall with the two-storey transmission hall to see where the machines stood and where the switchgear was housed.
The tailrace power station beside it is tiny by comparison; seen together, the two explain how the same water generated power twice.
Visiting
The main building served as the Former Yaotsu Power Plant Museum, but interior access has been suspended since December 29, 2018, and the grounds beyond the gate are closed (Yaotsu Town), so the generators and cranes cannot be seen up close.
The exterior can be viewed from outside the gate. No official guidance on photography was found. Directions and parking are given on the page for the Former Yaotsu Power Plant Facilities as a whole.
Q&A
- Can I go inside the main building of the Former Yaotsu Power Plant Facilities?
- No. Interior access has been suspended since December 29, 2018, for seismic safety, and the area beyond the gate is closed (Yaotsu Town).
- When was the main building of the Former Yaotsu Power Plant Facilities built?
- Construction began in 1907 and was completed in 1911 (Agency for Cultural Affairs).
- What survives inside the Former Yaotsu Power Plant Facilities main building?
- Three generating units, one travelling crane and five sets of penstock channels are designated with the building; the steel penstocks are missing (Agency for Cultural Affairs).
- What is the tailrace power station of the Former Yaotsu Power Plant Facilities?
- A small plant that used the drop of the main building's discharge to generate more power; one generating unit and a crane remain (Agency for Cultural Affairs).
- When was the main building of the Former Yaotsu Power Plant Facilities designated an Important Cultural Property?
- On May 1, 1998 (Agency for Cultural Affairs).
Basic Information
| Name | Former Yaotsu Power Plant Facilities (旧八百津発電所施設), Main Building and Tailrace Power Station |
|---|---|
| Location | 1770-1 Yaotsu, Yaotsu Town, Kamo District, Gifu Prefecture |
| Designation | Important Cultural Property (Structure) |
| Year Designated | Designated 1998/05/01 (Heisei 10) |
| Quantity | 2 structures (main building, tailrace power station) |
| Dimensions | Generator hall: brick, 826.0 m², copper roof / Transmission hall: brick, 2 storeys, 475.5 m², copper roof / Discharge channel: concrete / Tailrace power station: brick, 83.2 m², tank 80.7 m² |
| Owner | Yaotsu Town |
| Public Access | Interior access suspended since 2018/12/29 (area beyond the gate closed) |
References
- Former Yaotsu Power Plant Facilities, Main Building (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/00004061
- Former Yaotsu Power Plant Facilities, Tailrace Power Station (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/1095
- Former Yaotsu Power Plant Facilities, Head Tank, detailed commentary (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/00004059
- Former Yaotsu Power Plant Facilities, Main Building (Cultural Heritage Online)
- https://online.bunka.go.jp/heritages/detail/124854
- Former Yaotsu Power Plant Facilities, Tailrace Power Station (Cultural Heritage Online)
- https://online.bunka.go.jp/db/heritages/detail/155635
- Former Yaotsu Power Plant Museum (Yaotsu Town, Japanese)
- https://www.town.yaotsu.lg.jp/1518.htm
- Suspension of interior access (Yaotsu Town, Japanese)
- https://www.town.yaotsu.lg.jp/item/6896.htm
Last verified: 2026.11.12
Cultural Treasures in the Same Area
All are within walking distance in the same area, so we recommend visiting them together.
- Former Yaotsu Power Plant Facility Power Plant Main Building 0.00 km
- Former Yaotsu Power Plant Facility Outfall Power Plant 0.06 km
