The John F. Kennedy Square is located in the center of Berlin’s souther district of Schöneberg. You can get there by taking the U4 and getting off at the nearby U Rathaus Schöneberg station.
The square was named after JFK on November 25th 1963, three days after his assassination.
The reason behind this is the US president’s visit earlier that year, during which he gave his famous “Ich bin ein Berliner” speach right on this square, on the stairs of the Schöneberg town hall
Today the square houses the Rathaus Schöneberg as well as other government buildings.