Walchensee or Lake Walchen is one of the deepest and largest alpine lakes in Germany, with a maximum depth of 192.3 metres and an area of 16.4 square kilometres. The lake is 75 kilometres south of Munich in the middle of the Bavarian Alps. The entire lake, including the island of Sassau, is within the municipality of Kochel. Landowner of the lake and island area is the Bavarian State. To the east and the south, the lake borders the municipality of Jachenau.