On the slopes of a natural north-to-south ridge near Rathmore, aerial photography revealed a faint, incomplete circular cropmark roughly 60 metres in diameter. Cropmarks form when buried features, old ditches, filled pits, or former walls, affect how crops grow above them, producing discolourations or variations in height that are invisible at ground level but legible from above. The circle here is tantalisingly incomplete; only its eastern extent could be clearly traced, leaving open the question of whether this was ever a fully enclosed space or simply the curved edge of an ancient field system.

What makes the site stranger still is what happened beneath it after it was photographed. The field was levelled, erasing whatever surface traces remained. Yet the landowner noticed something the machinery could not quite bury: the soil in the area was markedly darker than the surrounding ground, almost black, concentrated precisely where a larger adjacent enclosure had stood. Dark, organically rich soil of this kind often accumulates inside long-used enclosures where animal husbandry, habitation, and the slow deposit of waste build up over centuries. The possible enclosure does not sit alone. It is conjoined with at least three neighbouring enclosures to the north and northeast, suggesting this was once part of a denser cluster of activity rather than a single isolated feature. About 300 metres to the south, on the crest of the hill, sits the ringfort known as Rathmore, a more visible earthwork that lends its name to the townland and hints at the broader pattern of early medieval settlement across this ridge.