From Prague to vibrant Budapest, this Danube River cruise vacation takes you to four countries-each with its own beauty, history, and cultural treasures. Enjoy two nights in the "golden city" of Prague, one of Europe’s most beautiful cities. Stand in front of Old Town’s medieval Astronomical Clock, which amazes as an intricate timepiece and piece of art piece unlike anything else in the world. Travel to Nuremberg, Germany, to board your Avalon Suite Ship® on the Main Danube Canal and visit the 1000-year-old city with a Local Guide. Next, reach Regensburg, the only German city not bombed during WWII. Lovers of architecture will enjoy the many listed buildings of historic interest, and Porta Pretoria, gates to an ancient Roman fort built in 179 AD. Passau, known for its narrow, winding streets, offers the magnificent Italian baroque St. Stephen’s Cathedral. In Melk, you will visit Austria’s majestic Benedictine Abbey, one of Europe’s largest monasteries, which sits high on a bluff. Take in the breathtaking views before continuing through the picturesque Wachau Valley to the romantic sounds of Vienna, the "City of Music." Your European river cruise vacation ends in Budapest, the capital of Hungary, with guided sightseeing and free time to explore this vibrant city on your own.