For nearly 30 years, Berlin was divided not just by ideology, but by a concrete barrier that snaked through the city, serving as an ugly symbol of the Cold War. Erected in haste and torn down in protest, the Berlin Wall was almost 27 miles long and was protected with barbed wire, attack dogs, and 55,000 landmines. But though the wall stood between 1961 and 1989, it could not survive a massive democratic movement that ended up bringing down the the socialist German Democratic Republic (GDR) and spurring on the Cold War’s end.

The wall had its origins in the end of World War II, when Germany was carved into four pieces and occupied by Allied powers. Although Berlin was located about 90 miles east from the border between the GDR and West Germany and completely surrounded by the Soviet sector, the city was also originally divided into four quarters, but by 1947 was consolidated into east and west zones.

In 1949, the two new Germanies were officially founded. Socialist East Germany was wracked by poverty and convulsed by labor strikes in response to its new political and economic systems. The brain drain and worker shortage that resulted prompted the GDR to close its border with West Germany in 1952, making it much harder for people to cross from “Communist” to “free” Europe. (Revisit National Geographic's reporting from West Berlin before the wall fell.)

East Germans began fleeing through the more permeable border between East and West Berlin instead. At one point, 1,700 people a day sought refugee status by crossing from East to West Berlin, and about 3 million GDR citizens went to West Germany through the via West Berlin between 1949 and 1961.

In the wee hours of August 13, 1961, as Berliners slept, the GDR began building fences and barriers to seal off entry points from East Berlin into the western part of the city. The overnight move stunned Germans on both sides of the new border. As GDR soldiers patrolled the demarcation line and laborers began constructing a concrete wall, diplomatic officials and the militaries of both sides engaged in a series of tense standoffs.

View Images The Berlin Wall stretched for almost 27 miles across the city and employed landmines, dogs, and barbed wire to discourage escape attempts. Still, over 5,000 people managed to reach western Europe. Photograph by Norbert Enker, laif/Redux

Eventually, East Germany erected 27 miles of concrete wall through the city. The Wall was actually two parallel walls punctuated with guard towers and separated by the “death strip,” which included guard dog runs, landmines, barbed wire, and various obstacles designed to prevent escape. East German soldiers monitored the barriers 24/7, conducted surveillance on West Berlin, and had shoot-to-kill orders should they spot an escapee.

People did try to escape. Initially, they fled from houses right along the Wall; later, those houses were emptied and turned into fortifications for the Wall itself. Others plotted riskier escapes through tunnels, on hot air balloons, and even via train. Between 1961 and 1989, over 5,000 people made successful escapes. Others were not so lucky; at least 140 were killed or died while trying to cross the Wall.

Over the years, the Wall became a grim symbol of the Cold War. By 1989, many East Germans had had enough. They staged a series of mass demonstrations demanding democracy. Meanwhile, the Soviet bloc was destabilized by economic woes and political reforms. (Meet the forgotten 'wolf children' of World War II.)

View Images Businessman Alfine Fuad shows how he smuggled his family out of East Berlin through Checkpoint Charlie in 1976. Photograph by Chris Hoffmann, Picture alliance/Getty

On the night of November 9, 1989, East Berlin party official Günter Schabowski announced upcoming travel reforms in response to the protests, but botched the message so badly it sounded as if the GDR had in fact opened its borders. Thousands of East Berliners flooded toward border crossings along the Wall, where confused guards eventually opened the gates.

As East Berliners pushed through, tens of thousands of West Berliners met them in a massive outpouring of emotion and celebration. As they celebrated with champagne, music, and tears, Berliners began to literally tear down the wall with sledgehammers and chisels. Less than a month later, the GDR collapsed entirely, and in 1990, Germany reunified.