Under six metres, yet the girder is a large one
The Watarase Keikoku Railway Mizunumazawa Bridge is a railway bridge of 1912 at Mizunuma in Kurohonecho, Kiryu City, Gunma Prefecture, listed as a Registered Tangible Cultural Property in 2009. It spans 5.8 metres, which puts it among the smallest of the listed bridges on the line: one plain steel girder taking the track over a stream that runs down to the Watarase River.
The girder itself is not small. The Agency for Cultural Affairs identifies it as a 15 foot I-beam of the Tatsu No. 875 standard, among the largest I-beams produced under the standard designs of the Meiji and Taisho periods, a distinction it shares with the nearby Edogawa Bridge. A stiffener at midspan ties the two main beams together. Kiryu City reports that the maker's plate confirms manufacture by Kisha Seizo of Osaka in 1911.
The abutments are split stone laid in courses, described in the national record as finely built in a manner resembling English bond, with cobble work reinforcing the wing walls.
A listing that took in the smallest works too
The Watarase Keikoku Railway Mizunumazawa Bridge was registered on 2 November 2009, with public notice on the 19th of that month, as one of 38 structures listed together between Kiryu and Mato. No Japanese line had previously been registered in full across two prefectures. The criterion was contribution to the historic landscape of the country, and in 2016 the group was recognised as a Civil Engineering Heritage.
That a bridge under six metres long sits in the same listing as station buildings and the longest tunnel on the line says something about how the line was assessed. Built to move copper ore, it was assembled quickly from standard components ordered in bulk. The same girder types recur along the route, and because so many of them survive in place, the standard designs of the period can now be read across an entire working railway.
The name of the stream differs between sources. The Agency for Cultural Affairs calls it the Mizunumazawa; Kiryu City and the operator's leaflet call it the Dojirizawa.
Seen from the sports ground north of Mizunuma
Kiryu City places the Watarase Keikoku Railway Mizunumazawa Bridge about 350 metres northeast of Mizunuma Station. It can be seen from the prefectural road that runs along the south side of the track and from the open ground of the Mizunuma sports park, both close enough to reach on foot while waiting for a train.
The setting repays a look as well. The Satsuki Bridge crosses the Watarase River just to the north, and the buildings of Ryuzenji in the Yagihara district stand on the far bank. From a carriage the crossing takes about a minute out of Mizunuma towards Mato, or roughly four and a half minutes from Hanawa heading for Kiryu. The bridge is so short that many passengers pass over it without noticing.
Visiting
The Watarase Keikoku Railway Mizunumazawa Bridge is in service, so the deck and track area are closed. Because it can be viewed from a public road and from open parkland, it is one of the more accessible structures on the line. Mizunuma Station makes the natural base and has a hot spring attached. Walking about 600 metres southwest brings you to the Fudosawa Bridge, so the two can be compared in one visit.
Services are infrequent, so check the timetable before setting out. A one day free pass costs 1,880 yen for adults and 940 yen for children. Torokko trains require a seat coupon in addition to the ordinary fare, 700 yen for adults and 350 yen for children from 1 September 2026. Photography from public ground is unrestricted, while drone filming of trains and of the track area is prohibited. Ticket information is on the operator's website; fares here were checked on 13 September 2026.
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Q&A
- How big is the Watarase Keikoku Railway Mizunumazawa Bridge?
- It spans 5.8 metres on a single steel girder. Small for the line, though the 15 foot I-beam is among the largest of the period's standard designs.
- Who made the girder of the Watarase Keikoku Railway Mizunumazawa Bridge?
- Kiryu City reports that the maker's plate records Kisha Seizo of Osaka, in 1911.
- Where can the Watarase Keikoku Railway Mizunumazawa Bridge be viewed?
- From the prefectural road south of the track and from the Mizunuma sports park, about 350 metres northeast of Mizunuma Station.
- Which stream does the Watarase Keikoku Railway Mizunumazawa Bridge cross?
- The national record names it the Mizunumazawa, while Kiryu City and the operator's leaflet call it the Dojirizawa. Sources differ.
- When does a train reach the Watarase Keikoku Railway Mizunumazawa Bridge?
- About a minute out of Mizunuma towards Mato, or roughly four and a half minutes from Hanawa heading towards Kiryu.
Basic Information
| Name | Watarase Keikoku Railway Mizunumazawa Bridge |
|---|---|
| Location | Mizunuma, Kurohonecho, Kiryu City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (structure) |
| Year Designated | Registered in 2009 (Heisei 21) |
| Quantity | 1 structure |
| Dimensions | Length 5.8 metres |
| Owner | Not recorded in the Agency for Cultural Affairs database; the line is operated by Watarase Keikoku Railway Co., Ltd. |
| Public Access | Deck closed to entry; seen from public roads and from trains |
References
- Agency for Cultural Affairs, National Cultural Properties Database: Watarase Keikoku Railway Mizunumazawa Bridge
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00007863
- Kiryu City: nationally registered properties, Watarase Keikoku Railway
- https://www.city.kiryu.lg.jp/kankou/bunkazai/1010700/kunitouroku/1009117.html
- Watarase Keikoku Railway Co., Ltd.: cultural property leaflet
- https://www.watetsu.com/assets/pdf/sightseeing/culture_yukei_des02.pdf
- Watarase Keikoku Railway Co., Ltd.: one day free pass
- https://www.watetsu.com/rail-info/ticket_1dayfree.php
Last verified: 2026.09.13