Oboke Gorge

The Yoshino has cut down through crystalline schist here over a very long period, and the rock in the gorge walls is folded, striped and polished by the water into forms that have their own names - the geology is unusual enough to be a designated natural monument. The river is emerald where it is deep and white where it is not. Two ways to see it: a flat sightseeing boat runs a slow return trip of about half an hour through the calm section at Oboke, and upstream the same river carries commercial whitewater rafting, some of the better rapids in Japan, with grades that vary with the season and the release. Koboke, the adjoining gorge, is the rafting section proper. The Iya valley, with its vine bridges and steep hamlets, opens off the gorge and is the reason most people are in this part of Shikoku.

What you actually see

• Folded schist - striped and polished rock walls, a designated natural monument.
• The sightseeing boat - a half-hour return run through the calm section.
• Whitewater upstream - commercial rafting on some of Japan's better rapids.
• The Iya valley - vine bridges and steep hamlets opening off the gorge.

When to go

April to November; late November for colour in the gorge. Half a day.

Honest expectations

Boats and rafts stop in high water after rain. The sightseeing boat is short and gentle - it is not the rafting. Public transport into the Iya valley beyond the station is very limited. Autumn weekends congest the single road.

Nearby

The Iya vine bridges are east up the valley; Kotohira is north.