The Wisper is a 29,715 kilometer (18.6 mi) long river in Hesse, Germany, right tributary of the Rhine. Its source is in the western Taunus, Rheingau-Taunus-Kreis district, near a small village named Wisper (municipality Heidenrod). It flows southwest through a densely forested valley with some medieval castle ruins surrounded by a popular hiking area. A man-made lake, the Wispersee is stocked with trout and is a popular fishing destination. The Wisper flows into the Rhine at Lorch.