Berlin Brandenburg Airport (BER)

BER airport is south-east of Berlin, in fare zone C. The station is beneath Terminal 1, on level U2; from Terminal 2, go down to arrivals (E0) and follow the signs. The FEX express train leaves every 15 minutes, from 4:00 to 1:00, and takes about 14 minutes to Südkreuz, 19 to Potsdamer Platz and 23 to Hauptbahnhof. The S9 runs every 20 minutes via Alexanderplatz, Friedrichstraße and Hauptbahnhof. You need an ABC ticket, which you buy at the machines or in the BVG, VBB or S-Bahn apps; a paper one must be validated before boarding. For Potsdam there is a direct regional train, the RB22, every hour.