Kamikōchi, Mountain valley in Matsumoto, Japan

Kamikochi is a sedimentary plain in the Azusa River valley of the Hida Mountains, stretching about 10 km from Taisho Pond to Yokoo and up to 1 km wide, at roughly 1,500 m. It is thought to have formed when the Azusa River was dammed by an eruption of Shirataniyama in the Yakedake volcanic group, and the resulting pond filled with sediment. A braided channel and bare gravel beds run along the floor, with a thin road and a few red-roofed buildings near the lower center; wooded slopes rise on both sides.

In the 17th century a Matsumoto domain official's hut was built at Myojin for tree felling, the later Myojin-kan. In 1915 the eruption of Yake-dake dammed the Azusa River and created Taisho Pond. The area was designated a national Place of Scenic Beauty and Natural Monument in 1928, and a Special Place of Scenic Beauty and Special Natural Monument in 1952. Year-round private-car restrictions began in 1996.

The name Kamikochi derives from "Kamigakuchi", referring to Hotaka Shrine's deity Hotakami no Mikoto, who descended on Mount Hotaka and is enshrined at the shrine's Okumiya and Myojin Pond. The Kappa Bridge, a wooden suspension bridge over the Azusa River, is named after the water sprite of Japanese folklore. The Weston Festival is held annually on the first Saturday and Sunday of June.

Private cars are barred year-round on Route 24 from Nakanoyu; drivers park at Sawando or Akandana and take a shuttle bus or taxi. The road is closed to vehicles from about 16 November to 16 April, though the lit Kamikochi Tunnel allows walking access in winter. Kappa Bridge is about five minutes on foot from the bus terminal.

The pond the current text describes is Taisho Pond, but the sources place its formation in 1915 when the Yakedake eruption dammed the Azusa River. A lesser-known detail: the pond holds a intake dam for the Kasumizawa power station, installed in 1927, and dredging of accumulated sediment began in 1977.