Riverside beauty and a vibrant cultural scene blend together in Budapest to form one of Europe's most rewarding cities. Hungary's enchanting capital straddles the banks of the Danube, with traditional hillside Buda on one side and modern Pest on the other. By day, stunning art nouveau buildings, stalwart castles and grand palaces set the stage for inspiring strolls and long soaks in thermal spas. By night, the shimmering lights of the Parliament building dance across the waters of the Danube, the Chain Bridge uniting it all as a dramatic centerpiece.

Budapest's old town is a fascinating medieval patchwork of narrow streets and colorful houses. In the Castle District, the Matthias Church soars in Gothic glory. Adjacent, the expansive wall and seven turrets of Fisherman's Bastion overlook the Danube, the graceful Chain Bridge and the Pest side of the river. The centerpiece of the district is the sprawling Buda Castle. Constructed in the 13th century and expanded to its current baroque splendor during the 18th century, this edifice was home to Hungary's kings for almost 700 years.

Renowned as the "City of Waltzes,” Austria's capital city of Vienna is Europe's center of classical music. Strauss and Mozart composed many of their finest pieces here. Vienna's musical history is matched by the elegant, graceful architecture that lines the Ringstrasse, the wide boulevard encircling the Inner City. Baroque, neo-Renaissance, Gothic-Romanesque and other splendidly styled structures, from the Hofburg Palace to the Vienna State Opera, take the breath away with their grand facades. Vienna has a more intimate side too: inviting footpaths lead through green parks and its famed Viennese cafés sweeten any stay with coffee and the city's delectable Sachertorte.

Vienna is considered one of Europe's greatest cultural hubs. Its art scene has long been established with the Hapsburg's collection of fine art, now housed at the Kunsthistorisches Museum. Today, Vienna's modern side showcases street art murals that don the side of buildings along the banks of the Danube. Ingrained in local life is the long-embraced tradition of coffeehouses; UNESCO includes Viennese coffeehouse culture on its list of Intangible Cultural Heritages. It is considered one of life's pleasures to while away an afternoon over an Einspänner coffee and a pastry.

Sail through a serene tapestry of terraced vineyards, forested slopes, charming towns and castle ruins in Austria's Wachau Valley, celebrated as perhaps the most scenic stretch of the Danube. Journey 18 miles through this vast UNESCO World Heritage Site, where the river courses through picturesque hillsides. Gaze upon the prolific grapevines and quaint wine-producing villages hugging the shores-the legacy of vintners that stretch as far back as Celtic and Roman times and an echo of the more than 30 monasteries that served as vineyards in Renaissance days.

Founded by the Celts over 2,000 years ago, Passau is one of Bavaria's oldest cities. Known as the "City of Three Rivers,” it rests at the confluence of the Inn, Ilz and Danube rivers. The city has long enjoyed its strategic position and grew to great economic and political power because of it. The legacy of its past prosperity lives on in graceful arcades, colorful houses with rococo facades and the glorious baroque St. Stephen's Cathedral, home to one of Europe's largest pipe organs. Passau is also where two nations meet; it is here that the German-Austrian border begins.

Having escaped major damage during World War II, the picturesque town of Regensburg is one of Europe's best-preserved medieval cities, the oldest city along the Danube and a UNESCO World Heritage Site. The Old Stone Bridge, constructed in the 12th century, is a masterpiece of medieval engineering with its 16 arches. St. Peter's Cathedral is widely considered Bavaria's best Gothic architectural work. The old town's Neupfarrplatz square is a cross section of history-it was once a thriving Jewish quarter, a bustling marketplace and the site of Nazi book burnings.

As far back as 1,200 years ago, visionary Frankish Emperor Charlemagne contemplated connecting the Rhine, Main and Danube Rivers so ships could travel the length of Europe. Today, his dream dramatically comes to life. The Main-Danube Canal employs 16 stair-step river locks that allow vessels to travel 2,200 miles through 10 countries, from the North Sea coast of Holland to the Black Sea shores of Romania.

Founded in 902, Bamberg remains a medieval-looking city known for its symphony orchestra and rauchbier, specialty smoked beer. The city's winding streets are filled with baroque patrician houses and are home to the stunning 11th-century Cathedral of Holy Roman Emperor Heinrich II, housing his tomb and that of Pope Clement II. Bamberg is especially noted for its Altes Rathaus, or Old Town Hall, situated on a twin-arched bridge over the Regnitz River, and for the old bishop's houses: the 16th-century Alte Hofhaltung (Old Court) and 17th-century Neue Residenz (New Residence).

Surrounded by Franconian vineyards, Würzburg was heavily damaged during World War II, but has since been completely restored. This prestigious university city is a jewel of baroque architecture. Its most pristine example of pomp and glory is the great Bishops' Residenz palace, built in 1744 for the prince-bishop; his unwavering support of artists is evidenced by the sweeping staircase and magnificent ceiling frescoes by Tiepolo. Other landmarks include the medieval, statue-lined Old Main Bridge and Marienberg Fortress, originally a Celtic hill fort and later residence of the bishops. The city remains a major wine-making center, hosting Germany's oldest and largest vineyard.

Journey along one of Germany's most important waterways today, passing landscapes that embody the country's scenic beauty and storybook charm. You will sail by quaint riverside villages, undulating farm country and the sylvan forests of the Spessart woodlands. Along the way, you just may lose yourself in the dreamy canvases of half-timbered houses, historic castles and splendid palaces. This is the Germany once ruled by dukes and brought to magical life by the imagination of the Brothers Grimm, who grew up in the town of Hanau and wove fantastic tales from these banks.

Koblenz is a traditional German city, founded more than 2,000 years ago. This former trading settlement rests on a massif of the Middle Rhine Highlands. Its cobblestone streets, wood-beamed houses adorned with flowers, ancient market square and medieval churches recall the fairy-tale Germany of old. At the "German Corner,” a massive equestrian statue of Prince William I observes the lovely riverside scene. The famed Teutonic Knights set up their first base here in 1216. The Romanesque Basilica of St. Castor, Koblenz's oldest building, dates to 836.

Cologne reveals its Roman heritage in its city layout and the ancient ruins that lie scattered through the town. Cologne's modern plazas and Hohe Strasse host welcoming shops, enticing restaurants and cologne boutiques. Of note is the city's 13th-century cathedral, a stunning example of Gothic artistry and a UNESCO World Heritage Site. Having survived Allied bombs during World War II, the cathedral's imposing twin spires are visible for miles and its stained glass windows fill the interior with brilliant colored light. Its steps lead to a platform with astounding views.

Sail the bucolic waters of the Rhine, deep into the Rhine–Meuse–Scheldt Delta, as classic Dutch landscapes unfurl all around. Flat farmland, charming windmills and svelte poplar trees line the shores, and vast tracts of land stretch in all directions, growing all manner of bounty, from tomatoes to tulips. Gaze upon Friesian cows and tidy villages with their neatly laid farmhouses and marvel at how much of this land was reclaimed from the sea, with the aid of traditional windmills and the construction of dikes.

Bid farewell to your fellow guests and journey home. Or spend more time exploring, perhaps joining one of our extensions.