Germany
Catch a ferry along the Elbe, the price of which is included in the price of a day ticket. A quick ride out from the Landungsbrücken to Övelgönne/Neumühlen or Teufelsbrück is not only a nice way to see the city from the water, but takes you straight to Hamburg's nicest beaches.
Public transport is run by HVV, whose website is excellent even if the English is a bit dodgy.
One last transport point: the 9 o'clock day ticket (valid from 9am until 6am the next day) is significantly cheaper than the standard day ticket if you don't need to travel during the morning rush hour.
Hamburg Public Transport: www.hvv.de
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