Vienna's extensive public transportation system, run by Wiener Linien (Vienna Transport Authority), is an easy and inexpensive way to get around town. The U-Bahn (metro) runs daily from 05:00 to 00:30, and non-stop on Fridays and Saturdays and before public holidays. Suburban S-Bahn trains radiate outwards from the city to the surrounding districts and towns. Trams are the best way to get around the inner city sights, running every 5-15 minutes between 05:00 and 00:30. Buses mostly serve Vienna's suburbs and most visitors won't need them though the handy night buses replace the U-Bahn from 00:45 to 05:00 on weekdays.
Tickets cost €2,40 for a single ride, though it's well worth getting a day ticket if you're planning on using public transport more than a few times. A 24-hour ticket costs €8, a 48-hour ticket €14,10 and a 72-hour ticket €17,10. Tickets must be validated before getting on board. Tickets can be purchased from multilingual machines at every U-Bahn station and on buses and trams, though single tickets bought on board cost €2,60 and only coins are accepted. You can also visit the ticket sales offices of Wiener Linien at the Stephansplatz, Karlsplatz, Westbahnhof and Wien Mitte U-Bahn stations. The 72 hour ticket can also be purchased at the Tourist Information Office. Children up to six years old always travel free; children up to 15 ride free on Sundays, holidays and during Vienna's school holidays (photo ID required). The Vienna Card offers 24, 48 and 72 hours of travel on public transport plus more than 210 discounts to museums, concerts, cafés, and more. It can be bought at the Tourist Information Offices or from the Wiener Linien offices.