Dillenburg lies on the eastern edge of the Westerwald range in the narrow valley of the river Dill emptying into the Lahn .
The river Dill flows from Hesse - Westphalia border to Wetzlar .
Dillenburg lies on the eastern edge of the Westerwald range in the narrow valley of the river Dill , which flows from Hesse - Westphalia border to Wetzlar , emptying into the Lahn .