Mettmann is a Kreis (district) in the middle of North Rhine-Westphalia, Germany. Neighboring are the Ennepe-Ruhr and the district-free cities Wuppertal, Solingen, Düsseldorf, Duisburg, Mülheim, Essen. It is the most densely populated rural district in Germany; it borders Düsseldorf International Airport in the northwestern district borders, on the city limits of Ratingen, and is also near Cologne Bonn Airport.