The Berlin Wall (German: Berliner Mauer, pronounced [bɛʁˌliːnɐ ˈmaʊ̯ɐ] (listen)) was a guarded concrete barrier that physically and ideologically divided Berlin from 1961 to 1989 as well as encircling and separating West Berlin from East German territory. Construction of the wall was commenced by the German Democratic Republic (GDR, East Germany) on 13 August 1961. The Wall cut off West Berlin from surrounding East Germany, including East Berlin. The barrier included guard towers placed along large concrete walls, accompanied by a wide area (later known as the "death strip") that contained anti-vehicle trenches, beds of nails and other defenses. The Eastern Bloc portrayed the Wall as protecting its population from fascist elements conspiring to prevent the "will of the people" from building a socialist state in East Germany.

GDR authorities officially referred to the Berlin Wall as the Anti-Fascist Protection Rampart (German: Antifaschistischer Schutzwall). The West Berlin city government sometimes referred to it as the "Wall of Shame", a term coined by mayor Willy Brandt in reference to the Wall's restriction on freedom of movement. Along with the separate and much longer Inner German border (IGB), which demarcated the border between East and West Germany, it came to symbolize physically the "Iron Curtain" that separated Western Europe and the Eastern Bloc during the Cold War.Before the Wall's erection, 3.5 million East Germans circumvented Eastern Bloc emigration restrictions and defected from the GDR, many by crossing over the border from East Berlin into West Berlin; from there they could then travel to West Germany and to other Western European countries. Between 1961 and 1989, the Wall prevented almost all such emigration. During this period, over 100,000 people attempted to escape, and over 5,000 people succeeded in escaping over the Wall, with an estimated death toll ranging from 136 to more than 200 in and around Berlin.

In 1989, a series of revolutions in nearby Eastern Bloc countries—in Poland and Hungary in particular—caused a chain reaction in East Germany. In particular, the Pan-European Picnic in August 1989 set in motion a peaceful development during which the Iron Curtain largely broke, the rulers in the East came under pressure, the Berlin Wall fell and finally the Eastern Bloc fell apart. After several weeks of civil unrest, the East German government announced on 9 November 1989 that all GDR citizens could visit West Germany and West Berlin. Crowds of East Germans crossed and climbed onto the Wall, joined by West Germans on the other side in a celebratory atmosphere. Over the next few weeks, the likes of souvenir hunters chipped away parts of the Wall. The Brandenburg Gate, a few meters from the Berlin Wall, was opened on 22 December 1989. The demolition of the Wall officially began on 13 June 1990 and was completed in 1994. The "fall of the Berlin Wall" paved the way for German reunification, which formally took place on 3 October 1990.