The Castle Mount is an elevation of the northern Harz foreland – southwest of Quedlinburg's old town. In the south and east it descends to the Mühlengraben (mill ditch), which branches off from the Bode. To the west is the Münzenberg (Coin Mount) with the Strohberg (Straw Mount) (182.6 m) on the other side. To the east is the Ochsenkopf (Ox head).
The sandstone Castle Mount belongs to the Quedlinburg Saddle. It is part of the stratigraphic ribbed landscape of the main natural unit group of the northern Harz foreland and divides it into the Blankenburg and Halberstadt depressions.
On the geologically unstable bedrock of the Castle Mount, the Quedlinburg monastery was founded in 936 by her son Otto I through the intercession of Mathilde, the widow of the East Franconian-German King Heinrich I, who died the same year. It is home to the Romanesque collegiate church of St. Servatius, which was essentially built between 1070 and 1129.