The Berlin Wall was a 156 km long, guarded, concrete barrier that separated East and West Berlin from 1961 to 1989.
After WWII, Germany was divided into 4 occupational zones, each one controlled by one of the Allied powers-USA, UK, France and the Soviet Union. Within only 2 years, tensions grew between the Soviet Union and the other occupying powers, mostly over the reconstruction plans for Germany. Once the war ended, the Soviet Union began instilling Communist governments across Eastern Europe, and planned to do the same with Germany. The Western powers refused. Although Berlin (the capital) was technically in the Soviets’ zone, it was further divided. Eastern Germans with like-mindedness, joined the Soviets, creating a new Soviet-style regime, and later the GDR. On the other site, the other Allied powers began building a material standard of living. Once this was achieved, East Germans began leaving in large numbers, fleeing the poverty, hunger and repression of the East for a better life in the West. And on August 13, 1961, the construction of the Wall commenced.
When the Iron Curtain fell in 1989, so did the Berlin Wall.