The Ilmenau is a river in Lower Saxony, Germany, which is one of the left tributaries of the Elbe. It originates in the Lüneburg Heath, south of Uelzen. It empties into the Elbe near Winsen (Luhe). The Ilmenau is 107 kilometres (66mi) long. The largest towns along the Ilmenau are Uelzen and Lüneburg. The city Ilmenau in Thuringia is not along the river Ilmenau but along the river Ilm (Thuringia).