Motosuko (L. Motosu) is the largest lake among the Fujigoko (Fuji Five Lakes) which spread in the north foot of Mt. Fuji. These lakes except Yamanakako are endorheic. Motosuko, Shojiko and Saiko are believed to have the same underground water vein as their water level moves in connection. Motosuko keeps the cleanest water characteristics among them as the population around the lake remains small.

The area is protected as part of the Fuji-Hakone-Izu National Park. In 2013, Fujisan and its related area, including Fujigoko, were registered as UNESCO World Heritage site.