Fotocredits
Matthias Naumann
Thomas Soddemann
Frankfurt am Main: Photo by Tobias Reich on Unsplash
Aachen: Photo by Alexander Schimmeck on Unsplash
Bonn: Photo by Reinhart Julian on Unsplash
Düsseldorf: Photo by Mika Baumeister on Unsplash
Köln: Photo by emrecan arık on Unsplash