Three Semicircles over a Stream
The Former JNR Miyanoharu Line Shioigawa Bridge (旧国鉄宮原線汐井川橋梁, Shioigawa Kyōryō) is a three-arch concrete railway bridge in the Kitazato district of Oguni Town, Kumamoto Prefecture, completed around 1938 and registered as a Registered Tangible Cultural Property in 2004.
It stands about 500 metres southeast of Horita Bridge, carrying the line over a stream in the Chikugo river system on three arches of 10 metres each. Doyama Bridge sits just to the south, on the far side of a small hill.
The name comes in three spellings, all pronounced Shioigawa: 汐井川 for the bridge, 塩井川 for the local address, and 潮井川 for the stream in the Agency for Cultural Affairs' description.
Why Shioigawa Matters
The registration criterion is contribution to the historic landscape. The Agency for Cultural Affairs describes the Former JNR Miyanoharu Line Shioigawa Bridge as a structure composed entirely of geometric shapes.
The arches are close to perfect semicircles, and the piers flare toward the base, as they do all along the line. With nothing but semicircles, trapezoids and a straight deck, the bridge's skeleton is legible from a long way off. It is a case of making a structure handsome by getting the shapes right rather than by adding ornament.
Except for the length of its piers it is nearly identical to Doyama Bridge, and the two, with the hill between them, form one landscape. Put the same design in two valleys and the difference in terrain turns into a difference in leg length.
What to Look For
Stand square to the bridge and check how close each arch comes to a true semicircle. Three equal half-circles in a row, flared legs between them: the Agency's phrase about geometric shapes is something you can trace with your eye.
Then go round to the Doyama side and compare the piers. With the arches identical, the difference is simply the depth of each valley.
Visiting
It lies outside the walking path the town maintains between Yu Station and the old Kitazato Station. The Japan Travel Bureau Foundation's survey notes that Konogawa and Kitazato are the two bridges easily reached on foot, so plan to come by car.
The town lists no parking or toilets for this bridge. The land around it is farmland and private property: stay on the road and do not walk into fields or onto the trackbed. There is no admission charge or booking. Doyama Bridge is close by, and seeing both across the hill is the best way to understand them.
- 📍 Plan Your Visit to Kumamoto
- Find tours, activities & transport passes near Former JNR Miyanoharu Line Shioigawa Bridge
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Q&A
- How do you pronounce the name of the Former JNR Miyanoharu Line Shioigawa Bridge?
- Shioigawa. The same sound is written three ways: 汐井川 for the bridge, 塩井川 for the address and 潮井川 for the stream.
- How long is the Former JNR Miyanoharu Line Shioigawa Bridge?
- The Agency for Cultural Affairs database gives 36 metres in its structure field and 34 metres in the descriptive text of the same record, so the sources differ.
- Can I see the Former JNR Miyanoharu Line Shioigawa Bridge from the walking path?
- No. It lies outside the maintained path, so drive there and view it from the road.
- When was the Former JNR Miyanoharu Line Shioigawa Bridge built?
- It was completed around 1938 and registered as a Registered Tangible Cultural Property in 2004.
- How is the Former JNR Miyanoharu Line Shioigawa Bridge related to Doyama Bridge?
- The Agency for Cultural Affairs says the two are almost identical in form and scale apart from their piers, and that with the hill between them they form a single landscape.
Basic Information
| Name | Former JNR Miyanoharu Line Shioigawa Bridge |
|---|---|
| Location | Aza Shioigawa, Oaza Kitazato, Oguni Town, Aso District, Kumamoto Prefecture |
| Designation | Registered Tangible Cultural Property (Building) |
| Year Designated | Registered 2004/2/17 (Heisei 16) |
| Quantity | 1 structure |
| Dimensions | 3-span concrete arch bridge, 36 metres long (34 metres in the descriptive text) |
| Owner | Oguni Town |
| Public Access | Exterior only (view from the road) |
References
- Database of National Cultural Properties: Former JNR Miyanoharu Line Shioigawa Bridge (Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00003922
- Cultural Heritage Online: Former JNR Miyanoharu Line Shioigawa Bridge
- https://online.bunka.go.jp/heritages/detail/169232
- Database of National Cultural Properties: Former JNR Miyanoharu Line Doyama Bridge (Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00003923
- Concrete arch bridges of the former JNR Miyanoharu Line (Japan Travel Bureau Foundation)
- https://tabi.jtb.or.jp/res/430298-
- Former JNR Miyanoharu Line Walking (Oguni Town official tourism site)
- https://www.town.kumamoto-oguni.lg.jp/kankojyoho/kanko_taiken/20269
Last verified: 2026.09.25
