The Karl-Marx-Allee is a monumental socialist boulevard built by the young GDR between 1952 and 1960 in Berlin Friedrichshain and Mitte. Today the boulevard is named after the political philosopher and social theorist Karl Marx.

It is probably the most monumental avenue building in the 20th century of Germany. The boulevard originally named Stalinallee until 1961, was a flagship building project of East Germany's reconstruction programme after World War II. It was designed by the architects Hartmann, Henselmann, Hopp, Leucht, Paulick and Souradny to contain spacious and luxurious apartments for plain workers, as well as shops, restaurants, cafés, a tourist hotel and an enormous cinema (the International).

The alley which is 90m wide and nearly 2km long, is lined with monumental eight-storey buildings designed in the so-called wedding-cake-style, the socialist classicism of the Soviet Union. The buildings differ the revetments of the facades which contain often equally, traditional Berlin motives by Karl Friedrich Schinkel. Most of the buildings are covered by architectural ceramics. Landmarks of the Karl-Marx-Allee are the two domed towers on Frankfurter Tor.

On June 17, 1953 the Stalinallee became focus of a worker's riot which endangered the young state's existence. Builders and construction workers demonstrated against the communist government which leads to a national uprising. The rebellion was quashed with tanks and troops of the Soviet Union and resulted in enormous loss of civil life.

Later the street was used for East Germany's annual May Day parade with thousands of goose-stepping soldiers, tanks and other military vehicles to show the power and the glory of the communist government.

After the German reunification most of the buildings including the two towers have been restored.

Today the Karl-Marx-Allee is a unique vivid open-air museum of Socialist architecture in Germany which is just as impressive today as the day it was completed.