Checkpoint Charlie was first set up in August 1961, when communist East Germany erected the Berlin Wall to prevent its citizens from fleeing to the democratic West. While it was only one of several crossings in and around Berlin—there was also a Checkpoint Alpha and Bravo—Charlie was notable for its location on Friedrichstrasse, a historic street in the American-occupied city center. Even more important was that it was the only gateway where East Germany allowed Allied diplomats, military personnel and foreign tourists to pass into Berlin’s Soviet sector. In response, the United States, France and Britain stationed military police at Checkpoint Charlie to ensure their officials had ready access to the border. The Allied guards spent most of their time monitoring diplomatic and military traffic, but they were also on hand to register and provide information to travelers before they ventured beyond the Wall.

Despite remaining in operation for nearly three decades, the Allied side of Checkpoint Charlie consisted of only a tiny prefabricated shack and a few sandbags. The original wooden guardhouse was replaced by a larger metal building in the 1980s, but the Allies always kept their operation simple as a way of symbolizing their view that the Berlin Wall was not a permanent or legitimate border. This stood in contrast to the more elaborate East German side of the checkpoint, which boasted guard towers, cement barriers and a shed where departing vehicles underwent searches and heat scans to ensure they weren’t hiding fugitives. Non-military travelers were often subject to intense scrutiny before being allowed to pass the East German border, and guards were known to confiscate any newspapers or literature that contradicted communist ideology.

One of the most nail-biting chapters of the Cold War began on October 22, 1961, when U.S. diplomat Allan Lightner attempted to cross Checkpoint Charlie to attend the opera in East Berlin. East German border guards demanded to see Lightner’s passport, but he refused on the grounds that only Soviet officials had the authority to inspect his papers. He only got through the checkpoint after he left and returned with a complement of armed U.S. soldiers and military jeeps. When East German officials continued to deny Americans entry into East Berlin, U.S. General Lucius Clay put on a show of force by moving 10 M-48 tanks into position around Checkpoint Charlie. The East Germans’ Soviet allies responded by positioning three-dozen T-55 tanks near the eastern border. On October 27, 10 of them rode forward to meet the American armor. For some 16 hours, the two sides stared each other down in one of the only armed confrontations of the Cold War. The potential for World War III was only averted when President John F. Kennedy contacted Soviet leader Nikita Khrushchev and convinced him to withdraw his tanks. A few minutes later, the American M-48s also left the scene.

In February 1962, Checkpoint Charlie played a supporting role in one of the most famous prisoner exchanges of the Cold War. The main swap took place at the nearby Glienicke Bridge, where captured American U-2 spy plane pilot Francis Gary Powers was traded for Rudolf Abel, a Soviet who had been arrested in New York and convicted of espionage. As Powers and Abel were crossing the bridge, Soviet officials at Checkpoint Charlie also released Frederic Pryor, an American student who had been arrested by the East German Stasi and mistakenly branded a spy. Checkpoint Charlie was later used for a few other prisoner swaps, and its role as a Cold War trading post became a popular motif in spy novels and films. One of the most famous depictions came in the 1965 film version of author John le Carré’s The Spy Who Came in from the Cold, which opens with a British agent being gunned down as he tries to cross the checkpoint.

In response to mass protests and international criticism, the East German government finally eased its travel restrictions on November 9, 1989. The new policy was supposed to take effect in an orderly fashion, but it turned into a free-for-all after a government official misspoke during a press conference and said the law was changing right away. That night, impromptu street parties broke out around Berlin. Thousands of East Germans gathered outside Checkpoint Charlie and other crossing points and began screaming for the guards to open the gates. Westerners stood on the other side and yelled for their countrymen to come over and join them. After a four-hour standoff, Checkpoint Charlie’s bewildered border guards finally opened the barriers, allowing people to move freely between East and West Berlin for the first time in nearly 30 years.

While the events of November 9, 1989, signaled the end of a divided Berlin, Checkpoint Charlie remained in operation until seven months later, when its famous beige guardhouse was removed during a ceremony attended by French, British, American, German and Soviet dignitaries. “For 29 years, Checkpoint Charlie embodied the cold war,” U.S. Secretary of State James Baker said during the proceedings. “We meet here today to dismantle it and to bury the conflict that created it.” A replica version of the guardhouse was later installed on Friedrichstrasse as a tourist attraction, but the original now sits on display at the Allied Museum in Berlin.