Head ashore to explore a Paleolithic site and an extraordinarily well-preserved medieval fortress. All along the way, history lies the banks of the river. Keep an eye out for Trajan’s Plaque, which the ancient Romans erected to commemorate the road they anchored in the steep cliffs above the water, and Golubac Castle, built in the 14th century and attacked successively by the Serbs, Magyars and Turks.

Featured Excursion: Lepenski Vir archaeological park and Golubac Castle

Unwind on board and cruise the breathtaking Iron Gates, an 83-mile-long (134-kilometer-long) stretch of scenic gorges that were cut through the Carpathian and Balkan mountains over eons by the Danube River. These gorges, which act as a natural border between Serbia and Romania, are among the most dramatic and beautiful sights in all of Europe. This was one of the swiftest and most dangerous stretches of the river before two dams were built: Iron Gate I and Iron Gate II. Construction on the dams began in 1964 and took 20 years to complete; they have dramatically altered the area’s landscape, raising the water level by 114 feet (35 meters) and drowning several islands and villages.

Vidin is a port town on the Danube that once played an important role in medieval Bulgarian politics, as the great fortress Baba Vida attests. It’s the base for an unusual excursion today, a visit to the fascinating Belogradchik rock formations. Or, head to a local’s home to bake a traditional Bulgarian dish called Banitsa.

Choice of Belogradchik red rock valley or Banitza home baking experience