What is the largest lake in Japan?

The largest lake in Japan is Lake Biwa. It lies entirely within Shiga Prefecture on Honshu, northeast of Kyoto, and covers about 670 square kilometres.

Lake Biwa is an ancient tectonic lake, estimated to be more than four million years old. Its long geological history has allowed a distinctive ecosystem to develop, including numerous fish and other species found nowhere else. The lake receives water from roughly 118 rivers and drains through the Seta River, which later becomes part of the Yodo River system and reaches Osaka Bay.

Lake Biwa has been important to Japanese culture for centuries. Its outline is traditionally said to resemble the biwa, a Japanese short-necked lute, which explains the lake’s name. Its proximity to Kyoto also made it a recurring subject in poetry, painting and historical writing.

It is more than a scenic landmark: Lake Biwa supplies drinking water to around 15 million people in the Kansai region. The Lake Biwa Canal, constructed in the late nineteenth century, also helped support Kyoto’s industrial recovery.