The name Verbindungsbahn (German for connection line) is used in Stuttgart to describe the underground connecting line between the subterranean S-Bahn Stuttgart station at Stuttgart Hauptbahnhof (Stuttgart Hbf, the Stuttgart main station) and the tunnel exit at the station in Stuttgart-Österfeld, which connects, via tunnel, the Stuttgart valley and the Filder plateau. The term originates from the planning stages in the 1960s, when similar projects for the S-Bahn München and S-Bahn Rhein-Main were given the same term.