Vienna has an extensive transportation network with a unified fare system that integrates municipal, regional and railway systems under the umbrella of the Verkehrsverbund Ost-Region (VOR). Public transport is provided by buses, trams and 5 underground metro lines (U-Bahn), most of which are operated by Vienna’s public transport network, Wiener Linien. There are also more than 50 suburban train (S-Bahn) stations within the city limits, and they are under the operation of Austria’s national railway system, ÖBB. With this abundance of access to public transport services, Vienna forms the hub of the Austrian railway system, with services to all parts of the country and abroad. The railway system connects Vienna with many other European cities such as Munich, Venice, Budapest, Prague, Bratislava and Zürich.