The are a mountain range to the west of Lake Biwa on the border of Shiga Prefecture and Kyoto Prefecture, Japan. The range runs north to south. It is narrowest in the southern part of the range, running east to west, and broadest at the northern part of the range, running km east to west. The eastern side of the Hira Mountains looks steeply over Lake Biwa, while the western side of the range forms a gentler valley in Kyoto.