01 / Dike
A 122 m dike in the Ure River bedrises like a horse's mane.

Umanoseiwa is a dike in the bed of the Ure River in Toyooka, Shinshiro, and a national natural monument. The city explains that after volcanic activity about 15 million years ago, lava flowed into cracks, and the dike stood up above its surroundings. It is 122 m long, 2.9 to 6.3 m wide and about 7 m high, and is described as the most typical example of this kind of dike.
- 122 m long
- About 7 m high
- National natural monument, 1934
