Lake Biwa

Lake Biwa is located entirely within Shiga Prefecture in west-central Honshu, Japan. As the nation's largest and most ancient freshwater lake, it covers approximately one-sixth of Shiga Prefecture's total area

The lake is located near Otsu city, the capital of Shiga.

It is located entirely within Shiga Prefecture (west-central Honshu), northeast of the former capital city of Kyoto. Lake Biwa is an ancient lake, over 4 million years old. It is the 13th oldest lake in the world. 

The learned monk of Enryaku-ji in the 14th century, gave a clue to the origin of the name Biwa-ko in his writing: "The lake is the Pure Land of the goddess Benzaiten because she lives on Chikubu Island and the shape of the lake is similar to that of the biwa, her favorite instrument.”

Lake Biwa is a breeding ground for freshwater fish, including trout, and for the pearl culture industry. Lake Biwa is of tectonic origin and is one of the world's oldest lakes, dating to at least 4 million years ago (mid-Pliocene). This long, uninterrupted period has allowed for a notably diverse ecosystem to evolve in the lake. Naturalists have documented more than 1000 species and subspecies in the lake, including about sixty endemics. Lake Biwa is an essential place for water birds. About 5,000 waterbirds visit Biwa every year.

The lake was designated as a UNESCO Ramsar Wetland (1993) in accordance with the Ramsar Convention. The object of this treaty is to protect and sensibly use internationally valuable wetlands.