The one at Ballynookery in County Cork does not even offer that much. It exists, as far as anyone can tell, only as a cropmark, a ghostly arc visible from the air when differential moisture in the soil causes overlying crops to grow at slightly different rates above buried features. A circular form roughly 46 metres across east to west was recorded in aerial photography, its southern and eastern arc just legible before it disappears beneath a farmyard that was built across it at some point, erasing whatever remained of that quadrant entirely.

Cropmarks are one of the quieter tools of landscape archaeology. A buried ditch, even one long since filled in and forgotten, retains moisture differently from the surrounding subsoil, and in dry conditions that contrast shows up in the crop above it, darker or taller along the line of the old cut. At Ballynookery the arc is consistent with a ringfort, the type of enclosed farmstead that was the most common form of rural settlement in early medieval Ireland, typically defined by one or more earthen banks and ditches encircling a domestic space. The diameter here falls comfortably within the typical range for such sites. Whether this was a ringfort, or something earlier or later, cannot be said with confidence from the aerial evidence alone, which is why the record designates it only as a possible enclosure.