The Aar Dam and its reservoir, the Aartalsee, lie in the upper Aar valley in the German state of Hesse. Since 1991 the dam has impounded the River Aar, a left-hand tributary of the Dill in the Gladenbach Uplands. The reservoir is also fed by the Stadterbach, Wilsbach (into the forebay), Weidbach and Meerbach (into the main reservoir).
