At the close of World War II, with Berlin in ruins and Europe exhausted from years of intense combat, the Iron Curtain fell across Germany. The Soviet Union claimed control of the eastern half, and the Allies claimed control of the west. But Berlin, despite being located deep in East Germany, also had a portion that was controlled by the Allies, and this isolated enclave served as a command post for many American and European spies operating in the Soviet Bloc.

As the Cold War deepened, tensions rose across Berlin and a brutal concrete wall was erected to separate the eastern and western halves of the city. At the same time, roads out of West Berlin were closed by the Soviets and its citizens were prevented from crossing into the surrounding country. One of these passages was the Glienicke Bridge (Glienicker Brücke in German), which the Soviets – with deep irony – called “The Bridge of Unity.” Overnight, fortifications were set up on either side of the bridge as Soviet and American-aligned troops faced off on either side. For many decades, nothing crossed the bridge other than hostile glances.

Glienicke Bridge

Cold water between East and West.

Except, in the dead of night, when groups of Soviet and American operatives would carefully walk out to the middle of the bridge for a covert exchange. Because it was one of the few neutral locations in the city, and because it was close to the American section of West Berlin, the Glienicke Bridge became the chosen site for prisoner exchanges between the KGB and the CIA. In the years from 1961-1986, dozens of spies were exchanged across the bridge and spirited back to their home countries.

Today, visitors to the bridge might never know that it has such a prominent place in the history of the Cold War. It is a simple bridge, open to cars and pedestrians and linking the outer limits of Berlin with the suburb of Potsdam. But in the center of the bridge, if you look closely, you can still see a faded white line marking the mid-point of the bridge. This is the exact spot where captured spies were once traded back and forth under the anxious guns of the world’s two great superpowers.