No earthwork breaks the surface, no stones mark its outline. The only evidence of its existence came from the air, when a aerial photograph taken in July 1989 caught a cropmark, the faint but telling discolouration of grass and crops that betrays buried archaeological features beneath. What emerged in that image was the outline of a roughly circular enclosure, approximately thirty metres across, defined by a fosse, essentially a ditch dug around a central area, which is one of the most common boundary features of early Irish enclosed settlements.

Cropmarks appear when buried ditches or pits retain more moisture than the surrounding soil, causing the vegetation above them to grow taller or stay greener during dry spells, or alternatively to ripen faster and show as lighter patches. The photograph in question, catalogued as GB89.V.12 and taken on 13 July 1989, revealed the curvilinear outline clearly enough to record it as a distinct archaeological feature. The enclosure sits on a ridge with the River Nore flowing roughly 160 metres to the south-west, a position typical of early medieval settlement sites in Ireland, where a slight elevation above water offered both drainage and visibility. A separate rectilinear enclosure lies immediately to the north-west, suggesting this corner of Lavistown preserves more than one phase or form of past land use.