Knap Hill is a promontory on the northern rim of the Vale of Pewsey, in northern Wiltshire, England, about a mile north of the village of Alton Priors. It lies between Golden Ball Hill, to the east, and Walker Hill, to the west. At the top of the hill is a causewayed enclosure, a form of Neolithic earthwork which began to appear in England from about 3700 BC, characterized by the full or partial enclosure of an area with ditches that are interrupted by gaps, or causeways.