Prospect Hill, which lies in the suburb, is Sydney's largest body of igneous rock and rises to a height of 117 metres above sea level. The Early Jurassic activity resulted in the shaping of the Prospect dolerite intrusion, which unequivocally points that the hill had a volcanic origin. The eroded residue of the volcanic core forms Prospect Hill, which was battered down over millions of years to a small bulge, which is a laccolith, in the generally flat lands of western Sydney.