The Limes Railway (German: Limesbahn) is a continuously electrified and single-track railway that runs on the southern edge of the Taunus in the German state of Hesse, connecting the towns of Niederhöchstadt and Bad Soden am Taunus.
The line is only 5.2 kilometres long and is served by S-Bahn line S3, connecting Bad Soden station—which is a terminus also used by the Soden Railway—via Frankfurt (Main) Hauptbahnhof to Frankfurt South station.
Beginning in 1964 a large greenfield housing development was built on the outskirts of Schwalbach am Taunus called Limesstadt, 'Limes city' (named after the Roman fortifications of the Limes Germanicus, which laid approximately 10 kilometres north of this site).
It was considered that this development needed the kind of public transport access that could only be provided by rail.
This idea was adopted by Georg Leber, the Federal Minister for Transport from 1966 to 1972 and the local member of the Bundestag.