Since the 19th century, these districts have grown together into a large complex with a vast industrial landscape, inhabited by some 7.3 million people, it is the fourth largest urban area in Europe after Moscow, London and Paris.
Since the 19th century, these districts have grown together into a large complex with a vast industrial landscape, inhabited by some 7.3 million people (when including (Düsseldorf) and (Wuppertal)). It is the fourth largest urban area in Europe after Moscow, London and Paris.