There were nine border crossings between East and West Berlin. These allowed visits by West Berliners, other West Germans, Western foreigners and Allied personnel into East Berlin, as well as visits by GDR citizens and citizens of other socialist countries into West Berlin, provided that they held the necessary permits. These crossings were restricted according to which nationality was allowed to use it (East Germans, West Germans, West Berliners, other countries). The best known was the vehicle and pedestrian checkpoint at the corner of Friedrichstraße and Zimmerstraße (Checkpoint Charlie), which was restricted to Allied personnel and foreigners.