A 98m circular ditched enclosure, intersected by the second and third Walton Roman camps (NPRNs 306332 & 306333), discovered in 1967 during Cambridge University aerial photography (CUCAP ASS99 & AST3). It's location close to the Roman camps had long made it a contender for a Roman gyrus, a circular wooden arena for training horses (Gibson 1999, 8). A small scale excavation by the Clwyd-Powys Archaeological Trust 2009 confirmed that the circular enclosure was earlier than the Roman camps, and the ditch was partly infilled by the Early Bronze Age, 2570-2300 cal. BC, making a late Neolithic date most likely. It may be a late henge monument or a very large funerary enclosure. The gyrus theory has now been disproved.

Information from Nigel Jones, CPAT, 2012.

Source: Gibson 1999 'The Walton Basin Project' CBA Research Report 118.

T. Driver, RCAHMW, 24th Jan 2011.