Berlin is in Germany.
Berlin . Located in northeastern Germany on the banks of the rivers Spree and Havel , it is the centre of the Berlin-Brandenburg Metropolitan Region , which has roughly 6 million residents from more than 180 nations . First documented in the 13th century and situated at the crossing of two important historic trade routes , Berlin became the capital of the Margraviate of Brandenburg ( 14171701 ) , the Kingdom of Prussia ( 1701 -- 1918 ) , the German Empire ( 1871 -- 1918 ) , the Weimar Republic ( 1919 -- 1933 ) and the Third Reich ( 1933 -- 1945 ) . Following German reunification in 1990 , Berlin once again became the capital of all-Germany . Nazi Germany is the common English name for the period in German history from 1933 to 1945 , when Germany was governed by a dictatorship under the control of Adolf Hitler and the Nazi Party ( NSDAP ) .