Bogensee is a lake in Berlin, Germany. It is bordered by Wandlitz, Prenden and Klosterfelde in the state of Brandenburg, about 15 km north of Berlin. The lake was artificially built here by the estate of Joseph Goebbels. The oval shaped lake covers an area of approximately 9,300 m², and is 180m in width (west to east) and 300m in length (south to north). The lake is a relic of the last ice age.