Lake Yamanaka is located in the village of Yamanakako in Yamanashi Prefecture near Mount Fuji, Japan.
Lake Yamanaka is the largest of the Fuji Five Lakes in surface area and the highest in elevation. It is the third highest lake in Japan, with a mean surface altitude of 980.5 metres. It is also the shallowest of the Fuji Five Lakes, with a maximum water depth of 13.5 metres. It was formed by lava flows from an ancient eruption of Mount Fuji. It is drained by the Sagami River and is the only of the Fuji Five Lakes to have a natural outflow.Carp, dace and smelt were introduced to the lake in the Meiji period, although early efforts to introduce sockeye salmon were not successful. In more recent years, introduced exotics such as black bass and bluegill have increasingly displaced native species. In terms of plant life, a variety of marimo was discovered in the lake in 1956.
Coordinates 35°25'8.031" N 138°52'27.848" E