Dillenburg is a town in Hesse's Gießen region in Germany. The town was formerly the seat of the old Dillkreis district, which is now part of the Lahn-Dill-Kreis.The town lies on the German-Dutch holiday road called the Orange Route, joining towns, cities and regions associated with the House of Orange-Nassau, as well as on the German Timber-Frame Road and the Rothaarsteig hiking trail.