 The city is "L"-shaped and stretches along the southwest shore of Lake Biwa, Japan's largest lake.Ōtsu ranges from the densely populated alluvium depressions near the shore of Lake Biwa to sparsely populated hilly and mountainous areas to the west (Hira Mountains and Mount Hiei) and south of the city.Lake Biwa, the largest freshwater lake in Japan, covers and is located at the center of the Shiga Prefecture.