The most recognized symbol of Berlin is situated on Paris Square in Mitte district. Classical triumphal gate was constructed during the rule of king of Prussia Friedrich Wilhelm II and was initially called Gate of Peace. Architect Karl Gotthard Langhans worked on the project in 1788-1791. In the 20th century the gate witnessed many important events in the history of Berlin, Germany and Europe. Before the unification of Germany, Brandenburg Gate was a symbol of the Cold War, being on the borderline between East and West Berlin. At that, it was not accessible from any side. In 1989 the main celebrations of the unification of the country took place around the gate.