Hachenburg is a town in the Westerwaldkreis in Rhineland-Palatinate, Germany.GeographyThe town lies in the Westerwald between Koblenz and Siegen, roughly 10 km west of Bad Marienberg on the river Nister. Hachenburg is the administrative seat of the Verbandsgemeinde of Hachenburg, a kind of collective municipality (See Verbandsgemeinde).