The Ruhr, also referred to as Ruhr area, 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 over 5 million, it is the largest urban area in Germany.

What is the Ruhr valley known for?

The Ruhr valley is a major industrial and mining region; it includes the industrial cities of Essen, Düsseldorf, and Dortmund. The Ruhr coalfield is one of the world's largest, and, although production had been curtailed sharply by the 21st century, it holds the bulk of Germany's proven bituminous coal reserves.

Why was the Ruhr Valley important to Germany?

The Ruhr Valley is important to Germany's economy for its quality farmland and its natural resources of coal and iron.