History of Berlin to intervene. In 1968 and after, West Berlin became one of the centers of the student revolt; in particular, the Kreuzberg borough was the center of many riots. The Fall of the Berlin Wall in November 1989 marks the end of the Cold War. On 9 November 1989, border guards allowed crowds from East Berlin to cross the frontier at the Bösebrücke. The guards believed that the authorities had decided to open the wall, but in reality no firm decision was taken and events gathered steam on their own. People of East and West Berlin climbed up and danced on
Berlin Wall that year (). Similar, very limited arrangements were made in 1964, 1965 and 1966. In 1971, with the Four Power Agreement on Berlin, agreements were reached that allowed West Berliners to apply for visas to enter East Berlin and East Germany regularly, comparable to the regulations already in force for West Germans. However, East German authorities could still refuse entry permits. East Berliners and East Germans could not, at first, travel to West Berlin or West Germany at all. This regulation remained in force essentially until the fall of the Wall, but over the years several exceptions to these rules