Daira Gorge and Ihai Rock
Daira Gorge is a 51-hectare ravine carved by the clear waters of the Fujikoto River. Over 30 meters deep in places, the gorge channels snowmelt from high in the mountains of Shirakami Sanchi. Its slopes are lined by a dense forest of Japanese beeches and 200-year-old Japanese cedars.
Although Daira Gorge lies outside the World Natural Heritage Site’s protected zone, its ecology is very similar. In addition to beech and cedar, the forest contains Japanese oak, horse chestnut, and several species of pine—roughly 100 tree species in all. More than 10 kinds of edible “mountain vegetables” (sansai) grow in the area. There are also fruit-bearing plants such as silver vine, a type of kiwifruit with leaves that turn a powdery white in summer. Sometimes called “cat powder,” silver vine produces a euphoric effect in cats more intense than that of catnip. Japanese wineberry, a species of raspberry, also grows here. Its local name is kuma-ichigo, meaning “bear strawberry,” as the sweet, red fruit is a favorite of Asian black bears living in the forest.
In addition to bears, Japanese macaques and Japanese flying squirrels make their homes in the Daira forest. Blue-and-white flycatchers and crested kingfishers flit among the trees. The damp forest floor sprouts many kinds of fungi, including the slender yellow fingers of fairy club fungus. Edible hen-of-the-woods grows in frilly clusters on the trunks of Japanese oak trees.
The mountains surrounding Daira Gorge were mined for zinc, lead, copper, and tin until 1958, and railway tracks and the brick smokestack of a former smelting facility are still visible from some areas. The gorge was inhabited until the mid-twentieth century, and many of the area’s younger cedars were planted around that time.
To view the gorge, visitors can park near Daira Bridge, which spans the ravine at a height of 30 meters and offers a commanding view. A trail that descends into the gorge begins about 3 kilometers past Daira Bridge on the road to Dakedai Nature Education Forest. The trail is just under 1 kilometer round-trip, and leads to a secluded spot by the Fujikoto River where huge boulders make an ideal picnic and swimming area. The clear water—a striking blue in the deeper pools—flows over colorful river rocks. Many are green tuff, a sedimentary rock with a blue-green hue. Just upriver is a large stone slab called Ihai Rock, named for its resemblance to a Buddhist mortuary tablet (ihai). The trail used to continue beyond Ihai Rock, but a landslide in 2013 destroyed the last half-kilometer.
The trail follows the route of former logging paths, and is slippery and steep in places. Some visitors may find the footing difficult.