Ruhr
The Ruhr area ( ROOR; German: Ruhrgebiet [ˈʁuːɐ̯ɡəˌbiːt] , also Ruhrpott German pronunciation: [ˈʁuːɐ̯pɔt] ), also referred to as the Ruhr District, Ruhr Region, or Ruhr Valley, is a polycentric urban area in North Rhine-Westphalia, Germany. With a population density of 1,160/km2 and a population of over 5 million (2017), it is the largest urban area in Germany and the third largest in the European Union.