The Schlachtensee is a lake in the southwest of Berlin in the district Steglitz-Zehlendorf on the edge of the Grunewald. The village is named after the lake. Since 1920, the lake and the village belong to Berlin.
The hose-like Schlachtensee is the almost southernmost lake of the Grunewaldsecke, which belongs geologically to the Hochfläche Teltow and has evolved as a glacial trough some 15,000 years ago in the Brandenburg stage of the Vistula Ice Age. With a surface area of approximately 421,000 m² and a maximum depth of about 8.5 meters, it is one of the larger lakes in the Berlin urban area; The circumference is 5.5 kilometers.