The S-Bahn in Frankfurt Germany is the city's extensive urban rail
system. It links central Frankfurt Germany (Hauptbanhof station)
to the Frankfurt International Airport and other communities in the
S-Bahn Station in Frankfurt Germany
The S-Bahn trains normally run at ground level but occasionally
travel underground, like the U-Bahn. Passengers can travel on the S-Bahn
from Frankfurt Hauptbanhof to the Frankfurt Airport and on the Mainz.
From Mainz, one can take an inexpensive boat cruise down the
world-famous Rhine River.