This mountain range includes the extraordinary "iron mountain" of Erzberg, the basis of imperial Austria's industrial power, and borders the limestone Ennstal Alps, with grandiose rockfaces rising along the Gesäuse defile. Over 1 200m up, the Präbichl pass linking the Enns and the Mur allows for a pleasant journey from Hieflau to Leoben, characterised by long steep-sided sections.