The Aschentalshalbe is a mountain ridge between the Gödeckekopf and Adlersberg (to the west) and the Großer Knollen to the south. It lies south of the village of Sieber in the district of Osterode in the German state of Lower Saxony. The Harz Club trail no. 15 G runs over these three summits. The Aschentalshalbe is also the watershed between the Sieber and the Oder. The Aschentalshalbe was named after the Aschental ("Aschen valley"), a neighbouring valley of the Breitental, in which the Tiefenbeek flows.