Kamui Kotan Potholes

The Kamui Kotan pothole formations are a rare geological feature: small stones trapped in hollows in the riverbank bedrock have been set spinning by the current, grinding cylindrical potholes into the rock over long periods. These potholes extend for roughly 1,200 metres along the river. Designated by Asahikawa City as a tangible cultural property (natural monument), the site is also celebrated as part of the Japan Heritage story “Kamui Kotan — The Fierce Struggle of Demon and Hero Gods.”

Ainu tradition lives on here: local lore says the “footprints” left by the demon god Ninnekamui as he fled from the hero god Samaikuru remain as these potholes. On the rocks just upstream you can also see marks said to be the sword cuts made by Samaikuru. The site’s appeal lies in the interplay of nature’s sculptural power and the land’s rich mythic associations.

Potholes can be viewed from the riverside promenade and observation points, but wet rock surfaces are slippery — please wear sturdy, slip‑resistant footwear for a safe visit.