The Berliner Mauer, or Berlin Wall, was a barrier that divided East and West Berlin from 1961 to 1989. It was built by the government of East Germany to prevent citizens from fleeing to the West. The wall symbolized the Cold War division between the communist East and the democratic West. The wall was approximately 155 kilometers long and included guard towers and a no-man's land. Its fall on November 9, 1989, marked a significant moment in history, leading to the reunification of Germany and the end of the Cold War. Today, remnants of the wall serve as a reminder of this divided past.