Join Keith Christiansen for a summer art journey through Europe's historic heart, featuring a charming river cruise along the Moselle. The beautiful Moselle Valley is lined with incomparable cathedrals and splendid ruins, evidence of the powerful forces who've claimed this region, most notably, ancient Roman conquerors who nurtured the valley's thriving vineyards. Yet, this small area of western Germany, eastern France, and Luxembourg is less renowned for its inspired, intimate art collections, hidden gems you'll see with Keith. Begin in the less-visited German cities of Frankfurt and Heidelberg. Take a curator-guided look at Frankfurt's outstanding Städel Museum, home to one of the world's most cherished European art collections. Visit medieval Heidelberg, with its romantic hilltop castle, and meet artists at the Heidelberger Kunstverein (HDKV), one of Germany's oldest art organizations. Then, transfer to the enchanting village of Cochem for your seven-night Moselle voyage on the newly renovated Princesse Royal, a Dutch-style riverboat with only 15 staterooms. Stop in delightful, underexplored towns, including Trier, Germany's oldest city, with its UNESCO-listed Roman monuments and medieval cathedrals, and Traben-Trarbach, with its sparkling Art Nouveau mansions. Disembark in Metz, France, for a tour of the massive, spellbinding Cathédrale Saint Etienne de Metz, featuring stained-glass windows from Marc Chagall. Conclude with two nights in Luxembourg for a rare exploration of its cultural gems, including the American WWII cemetery where General Patton is buried and the National Museum of History and Art.