We traveled by train for two hours from Warnemünde in northern Germany where the ship was docked into Berlin for the day.   The ride itself was worth it as we got to see a lot of the countryside.  We toured the city seeing all the relevant sites including the Berlin wall, Checkpoint Charlie and the Brandenburg Gate. 

In the afternoon we took a bus to Sachsenhausen, a German concentration camp that was a very sobering experience.  From there we took the train back to the ship. It was a very long day, but well worth it.