The Berlin Wall was a concrete manufacturing firm.
Berlin Wall . Constructed by the German Democratic Republic ( GDR , East Germany ) , starting on 13 August 1961 , the Wall completely cut off ( by land ) West Berlin from surrounding East Germany and from East Berlin until government officials opened it in November 1989 . In 1989 , a series of revolutions in nearby Eastern Bloc countries -- Poland and Hungary in particular -- caused a chain reaction in East Germany that ultimately resulted in the demise of the Wall . The fall of the Berlin Wall paved the way for German reunification , which was formally concluded on 3 October 1990 .