Three Spans at a River Confluence
The Watarase Keikoku Railway Ogurogawa Bridge (わたらせ渓谷鐵道小黒川橋梁) is a steel three-span girder bridge built in 1912 at the boundary of Azuma-cho, Midori City, and Kurohone-cho, Kiryu City, Gunma Prefecture, and was registered as a Registered Tangible Cultural Property (structure) on November 2, 2009 (Agency for Cultural Affairs).
The Agency for Cultural Affairs records a steel 3-span girder bridge 54 metres long, with abutments and piers, registration number 10-0290.
The Ashio Copper Railway
According to Watarase Keikoku Railway, the Ashio copper mine, bought by Furukawa Ichibei in 1877, grew to produce half of Japan's copper, more than horses and a horse tramway could carry, so a railway was built from Kiryu to Ashio. The Ashio Railway opened to Omama in 1911, reached Ashio in December 1912 and was completed to Ashio Honzan in 1914. Nationalised in 1918 as the Ashio Line, it has been run by Watarase Keikoku Railway since 1989.
The Watarase Keikoku Railway Ogurogawa Bridge spans the meeting of the Oguro and Watarase rivers, about 2,400 metres south-west of the Karasawa Bridge (Agency for Cultural Affairs).
Value as a Registered Cultural Property
The Watarase Keikoku Railway Ogurogawa Bridge was registered as a structure contributing to the historic landscape of the country. The Agency for Cultural Affairs notes its unusual design, with girder lengths varied to suit the spacing of piers standing on a midstream islet.
What to Look For
The Agency for Cultural Affairs describes three plate girders of 70, 60 and 30 feet, each of different length and depth, making a 54-metre bridge.
Watarase Keikoku Railway's pamphlet points out the large stone abutments and two piers, leaf-shaped in plan to cut water resistance; to the north lies the old Hanawa post town of the Copper Road.
Visiting
The Watarase Keikoku Railway Ogurogawa Bridge comes into view about three minutes after Mizunuma Station on a Mato-bound train, or about two and a half minutes after Hanawa Station on a Kiryu-bound train (Watarase Keikoku Railway). Watarase Keikoku Railway notes that all of its registered structures can be seen from the train.
Do not enter the tracks; view it from the train, the station or nearby roads. It is located at Azuma-cho, Midori City, and Mizunuma, Kurohone-cho, Kiryu City, Gunma Prefecture. Of the line's 38 registered structures, the 26 in Gunma and 11 in Tochigi are gathered on the group pages Watarase Keikoku Railway (Gunma Section) and Watarase Keikoku Railway (Tochigi Section).
- 📍 Plan Your Visit to Gunma
- Find tours, activities & transport passes near Watarase Keikoku Railway Ogurogawa Bridge
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Q&A
- When was it built?
- In 1912 (Agency for Cultural Affairs).
- How is it built?
- A steel 3-span girder bridge 54 metres long, with abutments and piers (Agency for Cultural Affairs).
- Why are the girders different lengths?
- They match the spacing of piers standing on a midstream islet (Agency for Cultural Affairs).
- Where can it be seen?
- The Watarase Keikoku Railway Ogurogawa Bridge comes into view about three minutes after Mizunuma Station on a Mato-bound train, or about two and a half minutes after Hanawa Station on a Kiryu-bound train (Watarase Keikoku Railway).
- When was the Watarase Keikoku Railway Ogurogawa Bridge registered?
- On November 2, 2009.
Basic Information
| Name | Watarase Keikoku Railway Ogurogawa Bridge (わたらせ渓谷鐵道小黒川橋梁) |
|---|---|
| Location | Azuma-cho, Midori City, and Mizunuma, Kurohone-cho, Kiryu City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (Structure) |
| Year Designated | Registered 2009/11/02 (Heisei 21) |
| Quantity | 1 structure |
| Dimensions | Steel 3-span girder bridge, length 54 metres, with abutments and piers |
| Owner | Not listed in the national database (line operated by Watarase Keikoku Railway Co., Ltd.) |
| Public Access | Visible from the train |
References
- Watarase Keikoku Railway Ogurogawa Bridge (Database of National Cultural Properties, Agency for Cultural Affairs)
- https://kunishitei.bunka.go.jp/heritage/detail/101/00007864
- Registered Tangible Cultural Properties (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/sightseeing/culture.php
- Pamphlet: Railway Heritage from the Train Window, map notes (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/assets/pdf/sightseeing/culture_yukei_des02.pdf
- History (Watarase Keikoku Railway, in Japanese)
- https://www.watetsu.com/company/history.php
Last verified: 2026.10.12
