What gives it away is a pattern of cropmarks, the faint differential in how crops grow over disturbed or differently compacted soil beneath, which in a July 1989 aerial photograph revealed at least ten circular patches arranged in a roughly L-shaped formation. The pattern runs approximately 200 metres from north to south through the centre of the field, with a shorter arm turning westward at the northern end.

Each circular mark is around 10 metres in diameter, and their shape closely resembles cropmarks recorded at a site called Conva, elsewhere in Cork, where similar marks were subsequently excavated and found to correspond to pits dug into the ground. Pits of this kind appear across prehistoric and early medieval Ireland in a variety of contexts, some associated with settlement, some with storage, some with ritual or industrial use, though without excavation at Ballycushen it is not possible to say which applies here. Crossing the field in a north-west to south-east direction are two parallel linear cropmarks, roughly 100 metres apart, which may represent the traces of field boundaries that were levelled at some point, perhaps centuries ago, leaving no surface trace but a lingering impression on what grows above them.

The site is, by its nature, one that exists most fully as an idea rather than a visible monument. Nothing marks the field itself. The evidence lives in an aerial photograph taken decades ago, in the geometry of a summer crop responding to what lies underground.