[1] The monument is north-east of the village of Marden, Wiltshire, within the Vale of Pewsey and between the World Heritage Sites of Avebury and Stonehenge.

[2] The enclosure is roughly oval in shape, and is enclosed by a typical bank and internal ditch arrangement constructed on the east, north and north-west sides and by the River Avon to the south and west.

[3][4] Its greatest width is 530 m and it encompasses an area of 14 hectares (35 acres),[5] and is under the care of English Heritage.

Antiquarian accounts of the site describe a huge mound within the enclosure called Hatfield Barrow, which collapsed after excavation by William Cunnington in the early 19th century.

[9] The site is included in a three-year investigation of the Pewsey Vale, beginning in 2015, by the Department of Archaeology at the University of Reading.