Saar, a river of Germany, a right-bank tributary of the Mosel. It rises in the Donon, an eminence of the Vosges, close to the Franco-German frontier, and flows at first north, then north-west and finally north again to its junction with the Mosel at Konz. Its length is 143 m. The middle part of its valley is an important industrial district, with coal-mines and a variety of manufactures; the Saar wines are also well known. The principal towns on the Saar are Saargemiind, Saarbrucken and St Johann (which face each other across the river), Saarlouis and Saarburg. The river is navigable up to Saargemiind, a distance of 75 m. From here there is connexion with the RhineMarne canal by way of the Saar canal, built in 1862, and 40 m. in length, following the Saar valley upwards for about half that distance.