Lake Ashi, Volcanic crater lake in Hakone, Japan.

Lake Ashi is a crater lake in Hakone at 723 meters elevation with forested shores and a view of Mount Fuji to the west. The water extends for several kilometers and three small ports connect the settlements around the lake.

Lake Ashi formed about 3,100 years ago when a steam explosion and pyroclastic flow caused part of Mount Hakone's Kamiyama cone to collapse, damming the Haya River in the caldera. In 757, the monk Manzan founded Hakone Shrine and, according to legend, subdued the nine-headed dragon of the lake. In 1670, the Fukara Aqueduct was completed, diverting lake water to Susono in Shizuoka.

The name Ashi-no-ko translates as Reed Lake referring to the water plants that once lined the shore. Today visitors board sightseeing boats to cross the water and see the mountain landscape or they walk the paths that run along the eastern and northern sides.

A walk along the northern shore takes about 30 to 40 minutes and passes through quiet sections with trees and open views of the water. The ropeway ends at Togendai on the western side and buses continue from there to other places in Hakone.

Lake Ashi is called the birthplace of bass fishing in Japan: in 1925, railway magnate Teijiro Akaboshi released largemouth bass here, the first stocking of the species in the country. The lake's native fish stocks were sparse, so rainbow trout, brown trout and other non-native fish were also introduced over the years.