Lake Motosu is one of the Fuji Five Lakes located at the northern base of Mount Fuji in Yamanashi Prefecture, Japan. Situated at an elevation of 900 meters, it is the westernmost and deepest of the five lakes, reaching a maximum depth of 138 meters. The lake gained international recognition when its image, featuring Mount Fuji's reflection on its waters, was selected for the reverse side of the 1,000 yen banknote issued in 2004 and continued on the 2024 redesign. This iconic view was originally captured by photographer Okada Kōyō in the early 20th century.
The lake holds geological significance as part of a larger body of water that once existed before Mount Fuji's eruption in 864 AD divided it into three separate lakes: Motosu, Shoji, and Sai. Despite this division, the three lakes remain connected by underground waterways, causing their water levels to rise and fall in unison. Lake Motosu is renowned for its exceptional water clarity and striking cobalt blue color, with visibility often exceeding 10 meters depth, making it a popular destination for divers and nature photographers.
Visitors to Lake Motosu can enjoy various activities throughout the year. The northern shore offers the best vantage points for viewing and photographing Mount Fuji's reflection, particularly during calm weather conditions. The lake is popular for camping, fishing for black bass and rainbow trout, kayaking, and stand-up paddleboarding. In winter, the area hosts the Fuji Shibazakura Festival nearby, though the lake itself remains accessible year-round. Several walking trails around the shoreline provide opportunities for hiking and nature observation through surrounding forests.
Lake Motosu is accessible from Tokyo by taking the JR Chuo Line to Otsuki Station, then transferring to the Fuji Kyuko Line to Kawaguchiko Station, a journey of approximately two hours. From Kawaguchiko Station, the Omni Bus Blue Line operates services to Lake Motosu, taking roughly 50 minutes. By car, the lake is approximately two hours from central Tokyo via the Chuo Expressway. There is no admission fee to access the lake and its public shoreline areas, though some campgrounds and facilities charge separate fees for their services.