Berlin Wall Monument (Chicago) described the effects of the wall and its ultimate fall by arguing that "It became the landmark that symbolized the Cold War… the Berlin Wall also left a lasting impression on the psyche of the German people". She further argues that The Berlin Wall "provides a salient and powerful example of how material culture intersects with knowledge production in the psychological sciences". Since the fall of the Berlin Wall on 9 November 1989, fragments of the Berlin Wall have been donated to various cities in the world. Chicago was offered a piece of the wall in 2008 by the German
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