Berlin is the capital and the largest city of Germany, as well as one of its 16 constituent states. With a steadily growing population of approximately 3.7 million, Berlin is the second most populous city proper in the European Union behind London and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of the rivers Spree and Havel, it is the centre of the Berlin-Brandenburg Metropolitan Region, which has roughly 6 million residents. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. Around one-third of the city's area is composed of forests, parks, gardens, rivers, canals and lakes.
First documented in the 13th century and situated at the crossing of two important historic trade routes, Berlin became the capital of the Margraviate of Brandenburg (1417–1701), the Kingdom of Prussia (1701–1918), the German Empire (1871–1918), the Weimar Republic (1919–1933) and the Third Reich (1933–1945). Berlin in the 1920s was the third largest municipality in the world. After World War II and its subsequent occupation by the victorious countries, the city was divided; East Berlin was declared capital of East Germany, while West Berlin became a de facto West German exclave, surrounded by the Berlin Wall (1961–1989) and East German territory. Following German reunification in 1990, Berlin once again became the capital of all of Germany.
Potsdam is the capital and largest city of the German federal state of Brandenburg. It directly borders the German capital, Berlin, and is part of the Berlin/Brandenburg Metropolitan Region. It is situated on the River Havel 24 kilometres (15 miles) southwest of Berlin's city centre.
Potsdam was a residence of the Prussian kings and the German Kaiser until 1918. Its planning embodied ideas of the Age of Enlightenment: through a careful balance of architecture and landscape, Potsdam was intended as "a picturesque, pastoral dream" which would remind its residents of their relationship with nature and reason.
Around the city there are a series of interconnected lakes and cultural landmarks, in particular the parks and palaces of Sanssouci, the largest World Heritage Site in Germany. The Potsdam Conference in 1945 was held at the palace Cecilienhof.
Babelsberg, in the south-eastern part of Potsdam, was a major film production studio before the 1930s and has enjoyed success as a major center of European film production since the fall of the Berlin Wall. The Filmstudio Babelsberg is the oldest large-scale film studio in the world.
Potsdam developed into a centre of science in Germany in the 19th century. Today, there are three public colleges, the University of Potsdam, and more than 30 research institutes in the city.