The Larger Tank, and the Arch Beneath the Road
The Head Tank for Units 2 and 3 of the Kyushu Electric Power Myoken Power Station (九州電力妙見発電所２号機及び３号機ヘッドタンク) is a stone water tank at Makizono-cho, Kirishima City, Kagoshima Prefecture, built in 1921 and entered on the national register of Tangible Cultural Properties on 26 January 2011 under registration number 46-0094. The Agency for Cultural Affairs records it as one unit of construction work with an area of 478 square metres.
It occupies the steep slope behind the stone powerhouse, set lower than the head tank that serves Unit 1. Where the upper tank is a compact cylinder, this one is rectangular in plan, its walls again built up in stepped courses of stone. Water enters from the Amorigawa (天降川), the river that runs past the powerhouse below, and leaves through penstocks feeding the second and third generating units.
The feature that makes this structure worth the climb is not the tank itself but what happens where its penstock crosses the road. The pipe passes underneath, and the masons carried the roadway over it on a stone arch. It is a small piece of work, easy to walk over without noticing, and it is the point where the whole site declares which building tradition it came from.
Why an Arch, in 1921
By the 1920s, a culvert of this kind would normally have been built in reinforced concrete. The material was available, cheaper in labour, and faster to place. The Myoken masons built an arch in cut stone instead.
Kagoshima has one of the strongest stone-arch traditions in Japan. Under the Shimazu domain and through the Meiji decades, masons in this region put up arched bridges across rivers throughout the province, working the local welded tuff into voussoirs that could carry a roadway on compression alone. That knowledge did not evaporate when concrete arrived. It was still resident in the hands of the men available for hire in 1921, and when a power company needed a road carried over a pipe, the obvious solution was the one the local trade already knew how to build well.
The result is a structure that sits oddly in the usual account of Japanese modernisation, which tends to describe a clean handover from timber and stone to iron and concrete. Here the sequence is muddled in the most interesting way: an electrical technology at the frontier of the era, built by craft methods inherited from the previous one, in a material quarried from the volcano next door.
Registered for the Landscape It Makes
Registered Tangible Cultural Property is a different category from Important Cultural Property. The register, established in 1996, works by notification rather than permission and was designed for modern structures still in active service, which describes this tank exactly. Three grounds for registration exist, and the one applied at Myoken is contribution to the historic landscape of the country.
That criterion is worth taking literally here, because the Agency's own description of this tank does so. Its closing sentence observes that the powerhouse and the run of stone tanks survive together and form a historic scene. The assessment is not simply that a 1921 water tank is old. It is that the powerhouse at the river, the lower rectangular tank, the upper cylindrical tank, the penstocks connecting them and the arch under the road remain as a set, and that the set is legible as a working landscape rather than as scattered relics.
Three registrations were made on the same day in January 2011: the main building at 46-0092, the Unit 1 head tank at 46-0093, and this tank at 46-0094. Reading the three entries in sequence gives a better picture of the site than any one of them alone.
Reading the Slope
Six times the area of the tank above it, and rectangular rather than round: the difference reflects the job. This tank feeds two generating units instead of one, and it holds water taken from the Amorigawa, a larger stream than the Nakatsugawa that supplies Unit 1. More flow to buffer, two penstocks to keep charged, a wider footprint to spread the load on the hillside.
The rectangular plan also fits the terrain in a way a cylinder would not. On a steep slope, a long tank set with its axis along the contour needs less cutting into the hill than a round tank of equal capacity, and the stepped courses of stone can be tied more directly into the retaining work on either side. The choice looks less like a stylistic decision than a reading of the ground.
Anyone tracing the water through the site ends up with a rough three-dimensional map in mind. Two intakes on two rivers. Two tanks at two heights, one round and one rectangular. Penstocks dropping down the slope, one of them more than 150 metres long. And at the bottom, against the river, the welded tuff powerhouse with three discharge channels returning the water to the Amorigawa. Every element is stone or steel, and every element is still doing what it was built to do.
Visiting the Site
This is company property attached to a working power station, and there is no public access, no admission and no published visiting hours. The road that crosses the penstock is the vantage point most visitors will have, and photography from public ground is unrestricted. Stepping onto the slope or approaching the tank is another matter, and permission should be sought from Kyushu Electric Power in advance rather than assumed.
The location is on the Amorigawa near the Myoken Onsen hot spring area of Makizono-cho, and access is easier than the rural address suggests. Kagoshima Airport is roughly fifteen minutes by car, as is the Mizobe Kagoshima Airport interchange on the Kyushu Expressway. By public transport, the Myoken route bus runs about seventeen minutes from Hayato Station on the JR Nippo Line and about ten minutes from Kareigawa Station on the JR Hisatsu Line, and airport buses between Kokubu Station and the airport stop at Myoken Onsen.
The valley deserves more than a photograph stop. Inns along this stretch of the Amorigawa draw naturally rising hot spring water at the riverbank, the gorge turns colour in November, and sweetfish anglers appear in the shallows in early summer. Kirishima Jingu, whose main hall is an Important Cultural Property, is within driving distance, and the wooden station building at Kareigawa, dating from 1903, is another registered structure ten minutes away. Kagoshima's stone arch bridges, the tradition that produced the small arch under this road, can be tracked down elsewhere in the prefecture for anyone who wants to follow the thread.
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Q&A
- What is the Myoken Power Station Units 2 and 3 Head Tank, and how does it differ from the Unit 1 tank?
- It is a stone water tank of 1921 on the slope behind the Myoken powerhouse in Kirishima City, holding water for the second and third generating units. It is rectangular in plan and covers 478 square metres, against the cylindrical Unit 1 tank of 76 square metres, and it sits lower on the same slope. It takes water from the Amorigawa, while the Unit 1 tank draws from the Nakatsugawa.
- What is the stone arch at the Myoken Power Station Units 2 and 3 Head Tank?
- The penstock leading from the tank passes beneath a road, and a stone arch was built to carry the roadway over the pipe. Cut stone rather than concrete was used, reflecting Kagoshima's long tradition of stone arch bridge construction, and it is one of the most distinctive details of the registered group.
- Can visitors see the Myoken Power Station Units 2 and 3 Head Tank, and is there an entry fee?
- There is no public access and no entry fee, since the tank stands on Kyushu Electric Power land forming part of an operating power station. The road crossing the penstock gives the usual view, and photography from public ground is unrestricted. Any closer approach requires advance contact with the company.
- When was the Myoken Power Station Units 2 and 3 Head Tank registered, and on what grounds?
- It was registered on 26 January 2011, number 46-0094, in the 69th round of registrations, under the criterion of contribution to the historic landscape of the country. The Agency for Cultural Affairs notes that the powerhouse and the series of stone tanks survive together and form that landscape.
- How do I get to the Myoken Power Station Units 2 and 3 Head Tank?
- It is about fifteen minutes by car from Kagoshima Airport or from the Mizobe Kagoshima Airport interchange on the Kyushu Expressway. By public transport, take the Myoken route bus roughly seventeen minutes from Hayato Station on the JR Nippo Line or about ten minutes from Kareigawa Station on the JR Hisatsu Line; airport buses between Kokubu Station and Kagoshima Airport also stop at Myoken Onsen.
Basic Information
| Name | Kyushu Electric Power Myoken Power Station Units 2 and 3 Head Tank (九州電力妙見発電所２号機及び３号機ヘッドタンク) |
|---|---|
| Location | 4224-6 Hakiri, Shukukubota, Makizono-cho, Kirishima City, Kagoshima Prefecture |
| Designation | Registered Tangible Cultural Property (Buildings), registration number 46-0094, 69th registration round, category of other structures |
| Year Designated | Registered 26 January 2011 (Heisei 23) |
| Quantity | 1 unit |
| Dimensions | Stone construction, area 478 square metres; rectangular tank of stepped stone courses; penstock passing beneath a road on a stone arch |
| Owner | Kyushu Electric Power Co., Inc. |
| Public Access | Not open to the public; part of an operating power station. Built 1921 (Taisho 10) |
References
- National Database of Cultural Properties, Agency for Cultural Affairs: Kyushu Electric Power Myoken Power Station Units 2 and 3 Head Tank
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00008607
- Kagoshima Cultural Properties Encyclopedia Plus: Myoken Power Station Units 2 and 3 Head Tank
- https://k-bunkazai.com/cultural/f-q-60092/
- National Database of Cultural Properties, Agency for Cultural Affairs: Myoken Power Station Main Building
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00008605
- National Database of Cultural Properties, Agency for Cultural Affairs: Myoken Power Station Unit 1 Head Tank
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00008606
- Kagoshima Prefecture Tourism Site: Myoken Onsen
- https://www.kagoshima-kankou.com/guide/10128
Last verified: 2026.07.30