Water crossing above the rails
The Watarase Keikoku Railway Teburiyama Aqueduct is a railway structure of 1930 at Kirihara in Omama, Midori City, Gunma Prefecture, listed as a Registered Tangible Cultural Property in 2009. A kakehi is a trough carried on supports, and this one exists to catch the rainwater and loose earth that come down a very steep slope and to send them over the line and into the Watarase River. The water does not pass under the railway. It goes over the top of it.
The trough is reinforced concrete, 14 metres long in the Agency for Cultural Affairs record and 14.3 metres by Midori City's measurement. What holds it up is a steel assembly in which posts and girder are made as one piece, built from second hand rail. Midori City reports that two of the rails still carry legible stampings, NO 75A 1907X and NO 75A 1907XI, marking them as Japanese rolled rail of 1907. Above the trough a catchment channel widens out like a trumpet mouth, gathering the runoff and funnelling it to this single point.
Worn out iron given a second job
The interest of the Watarase Keikoku Railway Teburiyama Aqueduct lies in an unglamorous piece of protective plant surviving with its methods intact. Railways replace rail on a cycle, and lifted rail was routinely reused on site as posts and beams. Surviving examples where the rolling year can still be read are far less common. Meiji era rail here holds up a Showa era structure and is still doing the work.
The listing was made on 2 November 2009, with public notice on the 19th of that month, when 38 structures between Kiryu and Mato were registered together. No other line in Japan had been listed in its entirety across two prefectures. The criterion was contribution to the historic landscape of the country, and the fact that a small piece of drainage plant was included alongside station buildings and bridges says a good deal about how the listing was framed. The group was named a Civil Engineering Heritage in 2016.
Fifteen metres short of a tunnel mouth
The Watarase Keikoku Railway Teburiyama Aqueduct stands roughly 15 metres southeast of the First Kanbai Tunnel, which means the train passes beneath it in the moment before entering the bore, or just after leaving it. Travelling from Omama towards Mato, it comes into view about three and a half minutes after departure, and within another minute the train has gone through the Third Kanbai Tunnel as well.
To catch it, look high in the window as the tunnel mouth approaches. Slim iron columns, a grey trough resting on them, and the catchment fanning out behind read less like railway equipment than like a small aqueduct. The slope it defends is the one the old copper road called the Seven Bends, and this structure is a later answer to the same terrain.
Visiting
The Watarase Keikoku Railway Teburiyama Aqueduct is part of a working railway and the track area is closed, so it is seen from trains between Omama and Kamikanbai. Because the structure passes overhead, an open sided Torokko carriage gives much the better view. Those trains run mainly from March to November and need a Torokko seat coupon in addition to the fare, 700 yen for adults and 350 yen for children from 1 September 2026.
The line covers 44.1 kilometres from Kiryu to Mato in about an hour and a half. If you plan to break the journey, the one day free pass costs 1,880 yen for adults and 940 yen for children. Photography from the carriage is unrestricted, while drone filming of trains and of the track area is prohibited. Timetables are on the operator's Torokko train page; fares here were checked on 13 September 2026.
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Q&A
- What is the Watarase Keikoku Railway Teburiyama Aqueduct for?
- It keeps rainwater and soil from a steep slope off the track by carrying them over the line and dropping them into the Watarase River.
- When was the Watarase Keikoku Railway Teburiyama Aqueduct built?
- In 1930. It became a Registered Tangible Cultural Property in 2009 as part of the line wide listing.
- Is the Watarase Keikoku Railway Teburiyama Aqueduct really built from old rail?
- Yes. Midori City records stampings such as NO 75A 1907X on the supports, showing that rail rolled in 1907 was reused for them.
- Where can the Watarase Keikoku Railway Teburiyama Aqueduct be seen?
- Between Omama and Kamikanbai, about three and a half minutes out of Omama towards Mato, immediately before the First Kanbai Tunnel.
- How large is the Watarase Keikoku Railway Teburiyama Aqueduct?
- The trough is 14 metres long in the national record and 14.3 metres by Midori City's measurement, about 2.7 metres wide, with a catchment channel above.
Basic Information
| Name | Watarase Keikoku Railway Teburiyama Aqueduct |
|---|---|
| Location | Kirihara, Omamacho, Midori City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (structure) |
| Year Designated | Registered in 2009 (Heisei 21) |
| Quantity | 1 structure |
| Dimensions | Length 14 metres (14.3 metres as measured by Midori City) |
| Owner | Not recorded in the Agency for Cultural Affairs database; the line is operated by Watarase Keikoku Railway Co., Ltd. |
| Public Access | Not open to entry; seen from passing trains |
References
- Agency for Cultural Affairs, National Cultural Properties Database: Watarase Keikoku Railway Teburiyama Aqueduct
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00007873
- Midori City: Teburiyama Aqueduct and First Kanbai Tunnel
- https://www.city.midori.gunma.jp/kosodate/1001647/1001800/1002430/1002484.html
- Watarase Keikoku Railway Co., Ltd.: cultural property leaflet
- https://www.watetsu.com/assets/pdf/sightseeing/culture_yukei_des01.pdf
- Watarase Keikoku Railway Co., Ltd.: Torokko Wasshi train
- https://www.watetsu.com/train/torowasshi.php
Last verified: 2026.09.13