The Düssel is a small right tributary of the River Rhine in North Rhine Westphalia, Germany. Its source is between Wülfrath and Velbert. It flows westward through the Neander Valley where the fossils of the first Neanderthal man were found in 1856. At Düsseldorf it forms a river delta by splitting into four streams (Nördliche Düssel, Südliche Düssel, Kittelbach, Brückerbach), which all join the Rhine after a few kilometers.