Strong and regal on its path, the Rhine River rules through Switzerland, France, Germany and the Netherlands. The crown jewels: the more than 40 castles lining his majestic banks; Cologne, dressed to impress with its towering Gothic cathedral; and the Alsatian town of Strasbourg, with a hereditary mix of French and German charm. Though “Father Rhine” is magnificent on his own, his siren-like German tributary, the Moselle, is impossible to ignore as she meanders past dramatic vineyard-clad landscapes and picturesque medieval village. Veering off to the east, another Rhine tributary awaits: the Main River, a knight in shining armor with half-timbered German towns where fairytales were born. Together, these waterways are the perfect royal trilogy for creating your own “once upon a time.”