John Wilmott (Telegraph, 29 Apr 2013) writes: Growing numbers are opting to take river cruises. Cruise lines are offering new twists on popular itineraries as well as the chance to navigate previously forgotten rivers. A river cruise holds obvious appeal for those seeking an unhurried holiday. As well as providing the opportunity to visit historic towns and cities, it allows you to enjoy beautiful scenery while relaxing on board a luxurious floating hotel. Europe’s key rivers, the Rhine, Main and Danube, are connected via a canal to form a continuous stream from the North Sea to the Black Sea. Forming the “veins” of France are the Rhône and the Saône, while Portugal is bisected by the Douro. The well-travelled can explore tributaries of the Rhine and Danube or the rivers of north-east Europe, such as the Elbe and Oder.