The Berlin Wall was a barrier constructed by the German Democratic Republic (GDR) starting on 13 August 1961, that completely cut off (by land) West Berlin from surrounding East Germany and from East Berlin. The barrier included guard towers placed along large concrete walls, which circumscribed a wide area that contained anti-vehicle trenches, "fakir beds" and other defenses. The fall of the Berlin Wall paved the way for German reunification, which was formally concluded on 3 October 1990.