The site at Canvarstown occupies dry ground on the northern slope of a roughly east-west valley, a slight rise that would have kept it clear of the marshy terrain surrounding it. At forty-nine metres across, it is a substantial monument, and the fact that it has been levelled almost to nothing makes the persistence of its outline all the more curious.

The enclosure came to wider attention through an aerial photograph taken between 1973 and 1977 (reference GSI S478), which revealed a cropmark of three concentric fosses. A fosse, in this context, is simply a ditch, and the presence of multiple concentric ones suggests an enclosure of some deliberate complexity, perhaps a defended settlement or a site of ceremonial significance, though the record does not specify its date or function. What the aerial image showed has since been partially confirmed at ground level: a flat circular area defined by a low scarp of around twenty centimetres, enclosed by a fosse roughly three metres wide and thirty centimetres deep, and bounded by an outer bank five metres wide. There also appears to be a causewayed entrance on the southern side, where a deliberate gap in the ditching would have allowed access. The cropmark evidence suggests at least one further outer bank and fosse beyond what is now physically traceable, particularly visible in the north-northeast and southeast portions of the site.

The monument sits in reclaimed agricultural land and offers fair to good views along the valley in most directions, which may well have been part of its original appeal to whoever chose the spot. At ground level, the traces are subtle, a slight flattening here, a shallow depression there, the kind of thing that resolves into meaning only once you understand the geometry beneath your feet.