Ashiu Forest

Ashiu is far from everything, and the rules keep it that way. Kyoto University has run it as a research forest since 1921: about 4,200 hectares between 355 and 959 meters, where the borders of Kyoto, Fukui and Shiga meet, with roughly half the area still natural forest. The university counts 243 woody plant species, 532 herbaceous species and 85 ferns. Deer grazing has thinned the undergrowth badly, and you may pass fenced research plots. The rules are strict. Entry is a day trip on foot only, from about mid-April to mid-December, and every group fills in an entry form at the office or the drop box. On your own you may walk only the forest road to Keyakizaka, the Bunanoki Pass trail and the old forest railway track, which since 2026 is open only to just before Takeyakuri Bridge because the bridge has deteriorated. The Kamitani valley, the big trees and everything else need a tour with a certified guide group. Kamitani involves more than 30 river crossings, so rubber boots are required. There is no mobile signal, and bears and mamushi vipers are common. The Kayabuki-no-sato thatched village is about 25 minutes back down the valley by car.