Stock Photo - Germany, Moselle, Bernkastel Kues. The Moselle is a river flowing through France, Luxembourg, and Germany. It is a left tributary of the Rhine, which it joins at Koblenz. A small part of Belgium is also drained by the Moselle through the Sauer and the Our. The Moselle ""twists and turns its way between Trier and Koblenz along one of Germany's most beautiful river valleys."" It flows through a region that has been influenced by mankind since it was first cultivated by the Romans. Today, its hillsides are covered by terraced vineyards where ""some of the best Rieslings grow"", and numerous ruined castles dominate the hilltops above wine villages and towns that line the riverbanks. Traben-Trarbach with its art nouveau architecture and Bernkastel-Kues with its traditional market square are two of the many popular tourist attractions on the Moselle river.