Proastiakos
The Proastiakos (Greek: Προαστιακός; "suburban") is Greece's commuter rail service, run by Hellenic Train, on rail infrastructure owned by the Hellenic Railways Organisation (OSE) (lines) and GAIAOSE (buildings and Trains). These services connect a participating city's central railway station to important locations such as a city's port or airport, as well as its suburbs and occasionally nearby towns and cities.