Bogensee is a small lake near Wandlitz in the German state of Brandenburg, located about 15 kilometres north of the Berlin city limits. The oval-shaped lake, a relic of the last ice age, is located on the Barnim Plateau and part of the Barnim Nature Park. It covers an area of approximately 9,200 m², and is 180 m in width and 300 m in length. The maximum depth is given as 2.5 m. The surrounding estates of Lanke manor were acquired by the City of Berlin in 1919. There are no buildings, paths or beaches directly on the banks of the lake. From Wikipedia