DE-7270981 Ruhrpott - largest urban area in Germany

The Ruhr (German: Ruhrgebiet) or the Ruhr district, Ruhr region, Ruhr area or Ruhr valley, is a polycentric urban area in North Rhine-Westphalia, Germany. Other colloquial names that are used include Ruhrpott, Revier or Kohlenpott.

With a population density of 2,800/km² and a population of over 5 million (2011), Ruhrpott is the largest urban area 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, which is among the largest in Europe.

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. 600,000), Essen (approx. 590,000) and Duisburg (approx. 500,000). Since the 19th century, these cities have grown together into a large complex with a vast industrial landscape, inhabited by some 7.3 million people (including Düsseldorf and Wuppertal). Historically, the western Ruhr towns, such as Duisburg and Essen, belong to the Rhineland, whereas the eastern part of the Ruhr, including Gelsenkirchen, Bochum, Dortmund and Hamm, were part of Westphalia.

The Ruhr area has no administrative center; each city in the area has its own administration, although there exists the supracommunal "Regionalverband Ruhr" institution in Essen. (Source: Wikipedia)

This multi-panel postcard came from Katrin (Postcrossing, July 2018).