Its outline only becomes legible from the air, and even then only under particular conditions, when a dry summer draws moisture unevenly from the soil and the buried past briefly reasserts itself as a pattern of differently coloured crops.

What aerial photography captured in July 1989 was a cropmark, the faint but readable trace of a buried fosse, or defensive ditch, curving from north around to south-southeast. Cropmarks of this kind appear because soil that was once disturbed, whether by digging a ditch or raising a bank, retains or loses moisture differently from the undisturbed ground around it. Crops rooted above a filled-in ditch grow more vigorously; those above compacted features struggle. From altitude, the differential ripens into a visible arc. The photograph in question was taken as part of the Cork Archaeological Survey aerial photography programme, and what it caught suggests the partial outline of a roughly circular or oval enclosure, though how much of it survives and what it once contained remain unknown. In the same field, linear cropmarks running to the east have been tentatively identified as the traces of levelled field boundaries, the kind of agricultural infrastructure that was once common across the Irish countryside and has been quietly erased over centuries of ploughing and land consolidation.