Neolithic causewayed enclosure near Avebury, comprising 3 concentric sub-circular circuits of interrupted bank and ditch: excavated 1922-3 by Rev. HGO Kendall, 1925-9 by Alexander Keiller, and subsequently in 1957 (Smith) and 1988 (Whittle). The enclosure is of early Neolithic origin, with evidence for some sporadic use continuing into the later Neolithic and beyond. In the Early Bronze Age, the site was a focus for the construction of round barrows (see associated monuments).The earthworks were surveyed by RCHME in 1990 at the request of Alasdair Whittle as part of his ongoing research into the Neolithic of the Avebury area. The site has been considered more fully by RCHME as part of the Industry and Enclosure in the Neolithic Project. See the project archive for full details. Kendall and Keillers work represented the first occasion on which an earthwork enclosure was shown clearly to have Neolithic origins. The interrupted nature of the enclosing earthworks was recognised as a deliberate feature. Other similarly constructed sites were seen to form a distinct class of Neolithic monument, originally referred to in the archaeological literature as causewayed camps. Keillers extensive excavations, coupled with the work of Stuart Piggot on the pottery in particular, meant that for a considerable period (until the 1960s), Windmill Hill was regarded as the type-site for the Neolithic of southern Britain.