In the middle of Friedrichstraße, Berlin's main traffic axis from north to south, a large mast with the image of a soldier rises into the sky. At the foot of the mast is a small wooden barrack with flags and sandbags. The sacks have long since been filled with concrete instead of sand and the barracks are a replica, but that doesn't change the popularity of the site: Checkpoint Charlie is one of the most exciting and well-known sights in Berlin. When Berlinw was divided into East and West, the former military checkpoint was controlled by the Americans. Only foreigners, employees of the Permanent Mission of the Federal Republic of Germany in the GDR, and GDR officials were allowed to cross the border here.