Karl-Marx-Allee (Karl Marx Avenue) is a prominent boulevard in the Berlin districts of Friedrichshain and Mitte, constructed and expanded by the former East Germany between 1949 and 1960 as a showcase of socialist urbanism and architectural grandeur. Originally named Stalinallee from 1949 to 1961, the boulevard formed the centrepiece of the German Democratic Republic's (GDR) postwar reconstruction efforts. It was conceived as a model of dignified workers' housing and civic life, designed by leading architects including Hermann Henselmann, Egon Hartmann, Hans Hopp, Kurt W. Leucht, Richard Paulick and Josef Souradny. The ensemble featured spacious residences, cultural institutions such as the Kino International, as well as restaurants, cafés, and a tourist hotel. These developments were emblematic of East Germany's ideological ambition to "elevate the proletariat" through state-led urban planning.
Stretching 2.3 kilometres (1.4 mi) and spanning 90 metres (300 ft) in width, Karl-Marx-Allee is lined with imposing eight-storey buildings rendered in the wedding-cake style of socialist classicism, reflecting the stylistic idiom of Stalinist architecture then prevalent in the Soviet Union. Notable landmarks include the twin towers at Frankfurter Tor and Strausberger Platz, both designed by Henselmann. The boulevard blends grandeur with local heritage, incorporating traditional Berlin motifs inspired by Karl Friedrich Schinkel, while façades were clad in ornate architectural ceramics. Though subject to decay by the late 1980s—with many tiles falling off, necessitating pedestrian shelters in some areas, the avenue remained widely admired. Philip Johnson referred to it as "true city planning on the grand scale," while Aldo Rossi declared it "Europe's last great street."