Ammersee (English: Lake Ammer) is a Zungenbecken lake in Upper Bavaria, Germany, southwest of Munich between the towns of Herrsching and Dießen am Ammersee. With a surface area of approximately , it is the sixth largest lake in Germany. The lake is at an elevation of , and has a maximum depth of . Like other Bavarian lakes, Ammersee developed as a result of the ice age glaciers melting. Ammersee is fed by the River Ammer, which flows as the Amper out of the lake. Like neighbouring Lake Starnberg, which is similar in size and shape, it is a popular location for watersports.