What reveals it is a cropmark, a phenomenon where buried archaeological features cause the vegetation growing over them to ripen or stress at a different rate from the surrounding soil, producing ghostly outlines that appear briefly in aerial photographs, usually during dry summers when the contrast between disturbed and undisturbed ground is at its sharpest.

What the aerial record shows at Cooladurragh is a bivallate enclosure, meaning one defined by two concentric banks or ditches rather than a single boundary. Its outline is subcircular, tending toward the oblong, with rounded corners, and measures approximately thirty metres across. That modest diameter is consistent with a range of early medieval enclosed settlements found throughout Ireland, where a ringwork of this kind would typically have contained a farmstead, its buildings, and ancillary structures within a defended perimeter. At Cooladurragh, the enclosure does not stand alone: additional linear cropmarks extend outward to the south and east, suggesting field boundaries, trackways, or further enclosures that once organised the landscape around the central settlement. Together, the marks sketch the faint geometry of a working agricultural complex, its ditches long silted, its banks long levelled, leaving no surface trace whatsoever.