The image, catalogued as CUCAP BGG047 and dated 16 July 1971, revealed what is known as a ring-ditch, the buried remains of a circular ditch that only becomes legible from the air, when differential moisture or soil conditions cause the vegetation above it to grow at a slightly different rate to its surroundings, producing what archaeologists call a cropmark.

Ring-ditches are among the quieter puzzles of Irish archaeology. They are generally interpreted as the eroded remnants of Bronze Age burial mounds, the encircling ditch that once surrounded a now-vanished earthen mound, though some may represent the foundations of circular structures used for other purposes. What is notable about Foulksrath is not this single example in isolation but the density of similar features in the surrounding landscape. A cluster of related ring-ditches has been recorded across the same stretch of the Nore valley, suggesting that this particular corridor of farmland was, at some point in prehistory, a place of repeated and deliberate activity, perhaps a funerary landscape where communities returned across generations to mark, bury, and commemorate. The valley's relatively flat, tillage-friendly ground has, ironically, been the condition both for the erasure of these monuments at surface level and for their survival as cropmarks detectable from above.