After the Nazi's defeat in World War II, Germany's capital of Berlin was bissected by a 155-kilometre long wall known as the Berlin Wall. The western side, known as West Germany, was occupied by the Allied forces. The eastern section, or East Germany, was occupied by the former Soviet Union.
This separation lasted through, and came to symbolise, the Cold War, when the tension between the nuclear-armed Americans and the Soviets--ideological proxies of capitalism and communism--was running high.
The Cold War ended with the reunification of Berlin in 1989, which literally saw the wall torn down, as family and friends came together after decades. It became one of the 20th century's most iconic historical moments.