Berlin is in northeastern Germany, in an area of low-lying marshy woodlands with a mainly flat topography, part of the vast Northern European Plain which stretches all the way from northern France to western Russia. The ''Berliner Urstromtal'' (an ice age glacial valley), between the low Barnim Plateau to the north and the Teltow plateau to the south, was formed by meltwater flowing from ice sheets at the end of the last Weichselian glaciation. The Spree follows this valley now. In Spandau, a borough in the west of Berlin, the Spree empties into the river Havel, which flows from north to south through western Berlin. The course of the Havel is more like a chain of lakes, the largest being the Tegeler See and the Großer Wannsee. A series of lakes also feeds into the upper Spree, which flows through the Großer Müggelsee in eastern Berlin.