High Quality Content by WIKIPEDIA articles! Schlachtensee is a lake in the south west of Berlin, in the Steglitz-Zehlendorf borough (between the quarters of Nikolassee and Zehlendorf), on the edge of the Grunewald forest. The lake lends its name to the surrounding area and to the nearby Studentendorf Schlachtensee, a student residence. The area has been part of Berlin since 1920.