Starting and ending in Cologne, this cruise takes you up the Rhine to its largest tributary, the Moselle River, and along the winding course of the Saar River, a tributary of the Moselle. As you cruise along the sinuous spine of the Mosel winegrowing region, admire its picturesque landscape dominated by steep vineyards. Explore Cochem’s narrow alleys, visit medieval Bernkastel-Kues, the fortified town of Saarlouis, and the capital of Germany’s state of Saarland, Saarbrücken, before continuing to one of the smallest sovereign states in Europe, Luxembourg. From the Sundeck, admire the most famous sight of Saarland: the Saarschleife, or Great Bend in the Saar River, where the Saar has carved a massive loop through quartzite rock. Visit the wine-growing town Grevenmacher and one of the four capitals of the European Union ­– Luxembourg City. At the confluence of the Saar and the Moselle rivers, Trier, Germany’s oldest city, awaits. Finally, visit Koblenz and Ehrenbreitstein Fortress on the Rhine before concluding your roundtrip. Due to low clearance heights at bridges and locks on the river route between Bernkastel and Saarlouis, access to the sun deck might be restricted for safety reasons.