West Lake is a lake located in Fuji Kawaguchiko Lake in Yamanashi Prefecture, Japan, is one of the five lakes of Fuji. West Lake is a fortified lake caused by the eruption of Mount Fuji. The area is the fourth largest of Fuji Lakes and the largest water depth is the second deep. In the past, it was probably a lake with Benqi Lake and Jingjin Lake, and was later divided into separate lakes due to the eruption of Mount Fuji lava flow.