It shows up only from the air, and only under the right conditions: a faint cropmark tracing the line of a fosse, the filled-in ditch that once defined the boundary of a circular enclosure roughly fifty metres across. A cropmark of this kind appears when buried ditches, which retain more moisture than the surrounding ground, cause the vegetation directly above them to grow fractionally taller or greener than the rest of the field. To a driver passing through, there is nothing to see. To a pilot with a camera and good timing, an ancient outline ghosts up through the grass.

The cropmark was captured in an aerial photograph taken in August 1984, as part of a systematic survey of Cork's archaeology from above. What the photograph revealed was not isolated. Immediately to the east lie the remains of a possible ringfort, and a second sits roughly two hundred metres to the east-northeast. Ringforts, the most common field monuments in Ireland, were typically enclosed farmsteads of the early medieval period, their circular banks and ditches defining a domestic space for a family and their livestock. Whether the Cloghleafin enclosure belongs to the same tradition, or represents something older or different in function, is not known. The cropmark alone cannot answer that question without excavation, and as far as the available record goes, the ground here has not been opened.