Seatallan begins at the Pots of Ashness, a broad grassy depression to the south of Haycock. From here a stiff ascent up what may have been a landslip leads directly to the summit. The top of the fell resembles a truncated cone, cut off at an angle and sloping away to the south. This cone in turn stands upon a much broader upland plateau which stretches away five miles to the south west. The River Bleng forms the entire western boundary, beginning on the slopes of Haycock and then flowing out in a huge loop to the south west. It finally joins the Irt and continues on to the sea at Ravenglass. The extremity of the Bleng's circuit, near to Gosforth, is given over to lowland cultivation and although belonging topographically to Seatallan could hardly be termed fellside. Higher up the south western shoulder are conifer plantations, both along the Bleng and above the Irt. Open fellside begins two miles south west of the summit.