Mainz is a West German city on the Rhine. It is the capital Rhineland-Palatinate and is located opposite Wiesbaden, the capital Hessen, not the larger Frankfurt am Main. The two cities are the only state capitals in Germany that border directly on each other.
Mainz can look back on a history of many centuries. This can be seen, among other things, in the many old buildings in the city. Like Mainz Cathedral (bottom left) or the Christuskirche (top).
The Citadel of Mainz is an other piece of history. It is located in the Old Town and was part of the Festung Mainz. The present form was built around 1660 and today serves as a venue for events and concerts.