The Frankfurter Tor ("Frankfurt Gate") is a large square in the inner-city Friedrichshain locality of Berlin, the capital city of Germany. It is situated in the centre of the district, at the intersection of Karl-Marx-Allee and Frankfurter Allee (the eastbound federal highways No. 1 and No. 5) with the Warschauer Straße and Petersburger Straße ring road (federal highway No. 96a). The Frankfurter Tor station, on the city's U-Bahn line U5, is located under the square.
The previously unnamed square received the name “Frankfurter Tor” on 8 November 1957 in the course of its reconstruction after World War II. The designation recalls both the nearby original location of the city gate that once provided access to the road to the city of Frankfurt (Oder) as well as the two former street names, Großer Frankfurter Straße and Frankfurter Allee, for the east–west axis of the major intersection at this location. These streets had both been renamed Stalinallee in 1949 in honor of the Soviet leader. In a clandestine operation in 1961 after Stalin’s personality cult had been denounced by the Soviet Union the western portion of Stalinallee, the former Großer Frankfurter Straße, was given the name Karl-Marx-Allee, and the eastern portion received back its former name, Frankfurter Allee.
The prominent twin towers on the western side of the square, significant examples of the Stalinist architectural style, were built between 1953 and 1956 as part of the Stalinallee ensemble according to plans by Hermann Henselmann. Their architecture evokes the idea of a city entrance (thus the designation “Tor”, gate, gateway), because the height of their domed towers and their location form a prominent beginning for today’s Karl-Marx-Allee, once the imposing western portion of Stalinallee. The tops of the two towers are in the style of the domes designed by Carl von Gontard for Gendarmenmarkt. The buildings, square and street intersection at Frankfurter Tor are a listed ensemble, protected for its historic relevance.
(This article incorporates information from the German Wikipedia)