Frankfurt Hauptbahnhof

Frankfurt Hauptbahnhof is a four-track S-Bahn station below Frankfurt Hauptbahnhof and as such part of the busiest railway station in Frankfurt, Germany. It is also the busiest rapid transit station in Frankfurt.

The underground station forms together with Hauptwache station and Konstablerwache station the key nodes in the network of the Rhine-Main S-Bahn, a rail network that serves the Frankfurt/Rhine-Main region. It connects with the surface platforms of regional and long-distance services and also interchanges with the U-Bahn and trams.

Source: Wikipedia