Berlin is big and spread out. Plan to rely on its excellent rail and bus system. The Berlin Welcome Card offers unlimited transportation for one adult and up to three children under 14, plus a discount of 25 percent or more to 120 cultural and sightseeing attractions. The 48-hour card is E16 and the 72-hour version costs E22. Sold at most train platforms.
A cheap, easy way to get to many Berlin sights is via the double-decker #100 bus that goes from the Bahnhof Zoo station to Alexanderplatz in the Mitte. It runs frequently, enabling sightseers to get on and off along the way at such attractions as the Kaiser-Wilhelm Memorial Church, the Siegessäule (Victory Column), the Tiergarten, Bellevue castle, the Reichstag, Brandenburg Gate, the Deutsche Staatsoper and St. Hedwigs Cathedral. Ride free with the Berlin WelcomeCard.