The spine of the Central Fells runs on a north–south axis with the highpoint at
High Raise. A complex system of daleheads to the east of this apex resolves itself into
Calf Crag, a broad-topped ridge featuring a number of rocky tops. This ridge then splits into two arms about the head of Greenburn, the southern branch running on to Gibson Knott and
Helm Crag. Between Calf Crag and Helm Crag the ridge narrows to perhaps a hundred yards in width, gradually curving to the south east on its one and a half mile course. There are several tops on this section, Gibson Knott being halfway along. The southern face above Far Easedale is rocky, Horn Crag being the principal feature. The northern side drops more gradually to the upper gathering grounds of Greenburn Bottom. There is little loss of height going westward from the summit before the climb to Calf Crag begins on a broadening ridge. Between Gibson Knott and Helm Crag lies the depression of Bracken Hause at around 1,100 ft. ==Geology==