The
Ruhr (, ), 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, which is among the largest in Europe.