Knapp and Barnett's Downs (grid reference SU030266) is a 71.4 hectare biological Site of Special Scientific Interest in Wiltshire, notified in 1971.

• Natural England citation sheet for the site (accessed 7 April 2022)

• Natural England website (SSSI information)

51°02′20″N 1°57′31″W / 51.03875°N 1.95859°W / 51.03875; -1.95859