river rising in the Belgian province of Luxembourg and flowing 107 miles (172 km) east and southeast into the Mosel (Moselle) River, 7 miles (11 km) southwest of Trier in Rhineland-Palatinate, Germany. The Sûre, which is navigable past Dekirche for about 40 miles (64 km), forms the Luxembourg–Germany border below the confluence of the Our River. It was the scene of severe fighting in the Battle of the Bulge during World War II.