The outlines, each measuring roughly 40 metres by 20 metres and together covering about two hectares, show up only as cropmarks, the faint differential in how vegetation grows over buried features. Soil disturbed by old ditches retains moisture differently from the ground around it, and under the right conditions, usually a dry summer, the grass or grain above will betray what lies beneath by growing slightly taller or greener.

Cropmarks of this kind have revealed prehistoric field systems, medieval boundaries, and forgotten enclosures across Ireland. The Graigue example, however, carries a gentle caveat. The two fields are so regular in their geometry, so evenly proportioned, that the most likely explanation is that they are simply modern in origin, the traces of relatively recent agricultural drainage or field division rather than anything ancient. That conclusion does not make them uninteresting, exactly, but it does explain why they were recorded with a degree of caution rather than enthusiasm. The aerial photograph that captured them, catalogued under the Cambridge University Collection of Aerial Photography reference BDI 87, preserves a moment of visibility that ground-level survey could never replicate.