Complex sentence: Berlin is located in eastern Germany, approximately west of the Polish border, 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.
Split into simpler sentences: Berlin is located in eastern Germany, approximately west of the Polish border, in an area of low-lying marshy woodlands with a mainly flat topography. It is part of the vast Northern European Plain which stretches all the way from northern France to western Russia.