Frankfurt is the commercial centre of Germany and the largest city in the state of Hesse. The city is known for its impressive skyline and the country's largest airport. Frankfurt is the location of the European Central Bank (ECB) and the Stock Exchange (DAX) and hosts many of Europe's largest trade fairs. Situated in the northwest Germany, where the river Dussel flows into the Rhine, Dusseldorf is one of Germany's financial, fashion and cultural capitals. It is the state capital of North-Rhine Westphalia, Germany's largest metropolitan region, consisting of over 11 million people.