01 / Sorachi Otaki potholes
47 potholes on the right bank,17 on the left, around the plunge pool.
Sorachi Otaki is a river fall where three rock strata, uplifted some 100 million years ago, interlock; its potholes are a Hokkaido-designated natural monument. Stones caught in cracks spun in the torrent to form them, and the description says they were exposed after the Takisato Dam's completion reduced the flow.
- Hokkaido natural monument
- 47 right bank, 17 left bank
- 3 strata uplifted ~100M years ago
