Essen is the central and, after Dortmund, second-largest city of the Ruhr, the largest urban area in Germany. Its population of 574,082 makes it the fourth-largest city of North Rhine-Westphalia after Cologne, Düsseldorf and Dortmund, as well as the tenth-largest city of Germany. Essen lies in the larger Rhine-Ruhr metropolitan region, second largest by GDP in the EU, and is part of the cultural area of Rhineland. Due to its central location in the Ruhr, Essen is often regarded as the Ruhr's "secret capital".