Discover Europe's Grand Castles

Below are a few of the grand castles and palaces that you can see while cruising along Europe's famed rivers. Each of these photogenic sights has a fascinating story to tell.

To see photos of these attractions, click the castle or palace name below.

Castles are common along the Rhine River -- a stretch known as the Upper Middle Rhine is home to more than 40 fortifications. Many Rhine itineraries include an excursion to the German city of Heidelberg, where the red sandstone Heidelberg Castle looms over the old town center. Once a grand Renaissance palace, the castle was destroyed during the Nine Years' War of the late 17th century. Some rebuilding was done (though never completed), and the edifice was later damaged by lightning strikes in 1764. The ruins caught the attention of 19th-century poets and artists and soon came to symbolize German Romanticism. Click here for Rhine River cruises that visit Heidelberg.

On the Mosel River, travelers can explore Cochem Castle, or Reichsburg, in Cochem, Germany. In 1294, King Adolf of Nassau pawned the castle and about 50 surrounding villages on royal land to the archbishop of Trier in order to finance his coronation as German emperor. Neither the king nor his heir could come up with the funds to reclaim the castle, and it remained with the Trier archbishops until 1794. The original structure fell to ruin, but in 1868, Berlin businessman Louis Ravené bought the site and rebuilt the castle around its Gothic foundations. Click here for Mosel River cruises that visit Cochem.

Climb up to the Imperial Castle for splendid views of Nuremberg, Germany, featured on Danube River sailings. It was one of the most important castles of the Holy Roman Empire during the Middle Ages. One of its oldest remaining parts is the double chapel -- two chapels with the same floor plans, one sitting atop the other. They are connected by an opening in the middle that allowed the congregation in either chapel to hear the service in the other one. Click here for Danube River cruises that visit Nuremberg.

Danube River itineraries also can provide an opportunity to visit the fairy-tale Neuschwanstein Castle in the Bavarian Alps. Neuschwanstein was built on its spectacular mountain perch from 1869 to 1886 by Ludwig II, sometimes called "Mad King Ludwig." After losing sovereignty in his kingdom, Ludwig withdrew into his own world of myths and legends and built elaborate royal residences where he could feel like a true king. Neuschwanstein is the most famous, and among its highlights is the Byzantine-style throne room with frescoes and cobalt blue columns and a grotto built to resemble a natural cave. Click here for Danube River itineraries that visit Neuschwanstein.

A stay in Prague is included on many departures on the Danube, Rhine and Elbe. Prague Castle is one of the world's largest castle complexes and the official residence of the president of the Czech Republic. Also called Hradcany Castle, after the neighborhood that surrounds it, it's comprised of palaces, churches, towers and gardens. The Bohemian Crown Jewels are housed here, though they're rarely displayed. These treasures are stored in what's been called the least accessible place in the castle -- an iron safe secured by seven locks. To open it, all seven keyholders -- which include the president and prime minister -- must be present. Click here for Danube, Rhine and Elbe trips that include a stop in Prague.

On Douro River cruises in Portugal, passengers usually head to Casa de Mateus during port calls in Regua. Built near the town of Vila Real in the first half of the 18th century, the palace is a fine example of Baroque architecture. Some might recognize it from the label that adorned flask-shaped bottles of Mateus rosé, a popular wine in the early 1970s. Mateus is most famous for its formal gardens, an elaborate display of topiaries, manicured hedges, tiered pools and a path shaded by a cypress tunnel. Click here for itineraries that visit Regua.