When your cruise ship docks at the port of Warnemünde, take an attraction-packed private excursion to Potsdam, a scenic town near Berlin that was long home to Prussian kings and German emperors. With your knowledgeable guide, design an itinerary that suits your particular interests. You may discover the lovely castle of Babelsberg, the lakeside Marble Palace or the breathtaking Sanssouci Palace. Or you could visit the Cecilienhof Palace,...