Lake Jusan is a brackish lake on the Sea of Japan in Goshogawara City in Aomori Prefecture. It is also called Jusan-gata. With a circumference of 30 km, an area of 2,060 ha and a depth of 3 m, it is the 3rd largest lake in the prefecture. It is known for a collecting ground for common clams (Corbiculidae).

The excavation research carried out in the 1990s revealed that Tosaminato, a legendary port city, which existed from the late 12th to the 15th centuries, was located on the sand bar between this lake and the Sea of Japan. As the home ground of the Abe and Ando clans, the powerful warrior families in the Tsugaru region, the city was prosperous as a port city, where international trade was actively carried on. It declined in the late 15th century with the ruin of the Ando clan.

A lot of historic sites, which prove the prosperity enjoyed by the Ando clan, remain in the area around Lake Jusan. Those include Sannobo Hie Shrine with the double Torii gate in Kyoto-style and the thirteen attached temples and Fukushima Castle ruins, where the Ando clan had resided.