Germany has more urban rail networks than any other country in Europe. This book introduces you not only to all the conventional metro systems (Berlin, Hamburg, Munich and Nuremberg), but also to those networks which at their station entrances boast a white U on a blue background, i.e. the systems that were originally designed to become proper metros in the long term: Frankfurt, Stuttgart, Cologne, Bonn, Dusseldorf, Duisburg, Essen/Mulheim, Bochum, Dortmund, Bielefeld and Hannover.