Ruhr 鲁尔区
The Ruhr (German pronunciation:[ˈʁuːɐ̯], German:Ruhrgebiet), or the Ruhr district, Ruhr region or Ruhr valley, is a polycentric 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, which is among the largest in Europe.