Hamburg

Hamburg  is the second largest city in Germany and the eighth largest city in the European Union. It is also the thirteenth largest German state. Its population is over 1.7 million people, and the Hamburg Metropolitan Region (including parts of the neighbouring Federal States of Lower Saxony and Schleswig-Holstein) has more than 5 million inhabitants. The city is situated on the river Elbe.

Germany

Munich

Munich is the capital and largest city of the German state of Bavaria, on the banks of River Isar north of the Bavarian Alps. Munich is the third largest city in Germany, after Berlin and Hamburg, with a population of around 1.49 million.  The Munich Metropolitan Region is home to 5.8 million people. The name of the city is derived from the Old High German term Munichen, meaning "by the monks". It derives from the monks of the Benedictine order who ran a monastery at the place that was later to become the Old Town of Munich; hence the monk depicted on the city's coat of arms. Munich was first mentioned in 1158. From 1255 the city was seat of the Bavarian Dukes. Black and gold — the colours of the Holy Roman Empire — have been the city's official colours since the time of Ludwig the Bavarian, when it was an imperial residence. Following a final reunification of the Wittelsbachian Duchy of Bavaria, previously divided and sub-divided for more than 200 years, the town became the country's sole capital in 1506. 

The Ruhr District

The Ruhr (German : Ruhrgebiet), or the Ruhr district, Ruhr region or Ruhr valley, is an urban area in North Rhine-Westphalia, Germany. With a population density of 2,800/km² and a population of eight and a half million, it is the largest urban agglomeration in Germany. It consists of several large, industrial cities bordered by the rivers Ruhr to the south, Rhine to the west, and Lippe to the north. In the southwest it borders the Bergisches Land. It is considered part of the larger Rhine-Ruhr metropolitan region of more than 12 million people. From west to east, the region includes the cities of Duisburg, Oberhausen, Bottrop, Mülheim an der Ruhr, Essen, Gelsenkirchen, Bochum, Herne, Hagen, Dortmund, and Hamm, as well as parts of the more "rural" districts of Wesel, Recklinghausen, Unna and Ennepe-Ruhr-Kreis. The most populous cities are Dortmund (approx. 572,000), Essen (approx. 566,000) and Duisburg (approx. 486,000).

Berlin

Berlin is the capital of Germany, and one of the 16 states of Germany. With a population of 3.5 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union. Located in northeastern Germany on the banks of River Spree, it is the center of the Berlin-Brandenburg Metropolitan Region, which has about 6 million residents from over 180 nations. 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 and lakes.