Rolling on the River.(The Good Life; TRAVEL)(cruise ships)

Byline: Sana Butler

Many of the world's great cities were built along rivers, making them easily accessible for trade and exploration. Today, riverboat cruises remain one of the most alluring and efficient ways to tour them. Like ocean liners, riverboats resemble floating hotels, but instead of carrying 2,000 passengers on the high seas, riverboats rarely hold more than 150 passengers, and they sail past fishing villages and vineyards to dock right in the heart of towns or medieval cities. In Europe, the Rhine and Danube are the hottest waterways for touring. Tauck organizes a 24-day Grand European Cruise through nine countries--including Germany, Croatia, Serbia, Bulgaria and Romania--to the Black Sea. Passengers awaken in a new city each day without the hassle of packing and unpacking. They stop long enough to walk to the ruins of a hilltop castle where Richard the Lion-Hearted was imprisoned in Durnstein, Austria, and study the architecture at the private library at the bishop's palace in Kalosca, Hungary (from $8,790; tauck.com).

The new eight-night Epicurean Adventurer Program from Uniworld starts in Marseille and goes through seven cities, ending in Lyon with an excursion to a Valrhona chocolate factory. The ship itself is luxuriously appointed, with spacious cabins, a hair salon and a masseuse on board (from $2,059; uniworld.com).

Sea Cloud--the Ritz Carlton of riverboats, with a Michelin-starred chef on board--traverses some of the same waterways but in a totally different style. On the 10-night Classic Rhine Golf Cruise, passengers schedule tee times all along the riverbanks, including at courses such as the Bickenbauer Golf Club near Munich and Pannonia Golf & Country Club between Vienna and Budapest (from $10,300). The seven-night Johann Strauss Waltz Music on the Danube cruise allows passengers to travel in the company of the famous composer's great-grandnephew, with stopovers for private concerts in opera houses along the way, as well as wine tastings at private chateaus owned by dukes and princesses. The company will even arrange to pick up guests' luggage in advance and have it waiting onboard when they ...