The ridge is formed from a sandstone outcrop of the Sherwood Sandstone Group, dating from the Early Triassic period around 250 million years ago. The sandstones are exposed forming extensive crags on the west flank of the northerly hill, as well as in smaller areas of the southerly hill. There are several natural caves. The two-storey cave known as Mad Allen's Hole (on the southerly hill at ) has an entrance partially blocked by boulders and is accessible via a circular hole at the rear. The Queen's Parlour, a large triple-chambered cave directly under the Raw Head trig point, might be partially quarried.