LANDESHAUPTSTADT Düsseldorf
The city that is really proud to be the capital of the largest Bundesland in the Bundesrepublik Deutschland, as they remind you about that almost every time. It is more Landeshauptstadtish than Hansestadts are Hansestadtish, or something.
That's shouldn't be surprising though, as when after the war the newly created state of North Rhine-Westphalia (that consists of three traditional regions – Rhineland, that was a part of Prussia before; Westphalia, that was also a part of Prussia (mostly); and Lippe, which used to be a separate state of the Weimar Republic, as the Free State of Lippe – Freistaat Lippe). This outcome meant that Düsseldorf, with mostly intact administrative buildings, was fairly central, between the two largest metro regions in the state and thus the British administration decided that it should be the capital.
But for important things – the city is technically a part of the Metropolregion Rhein-Ruhr, but practically it lies between the Köln+Bonn metro and Ruhrgebiet, similarly as Wuppertal. It is part of the Verkehrsverbund Rhein-Ruhr, so in the fare system it is integrated more with the Ruhrgebiet.
The city is known for its trade fair ground, Messe Düsseldorf (and the congress counterpart Convention Center Düsseldorf). It was founded in 1947, but moved to its current location in 1971, to the location that is close to the airport. It has a total exhibition space of 306 thousand m² (262.7 thousand m² indoors). Of course, this is where the DoKomi convention is held every years (including 2020 and 2021, nice). If you want to see how it looked like in 2020, please check my album: DoKomi 2020.