Not through stone or earthwork visible to a walker, but through the uneven way the grass grows, a phenomenon known as a cropmark. Where buried features such as ditches or walls lie beneath the surface, soil depth and moisture vary, and the vegetation above responds differently, growing lusher or more sparse depending on what lies underneath. From the ground, you would notice nothing unusual. From the air, the outline becomes legible.

This possible enclosure at Creggauns was identified not through conventional survey but through drone footage, which captured the differential grass growth clearly enough to suggest a circular monument of some antiquity. Enclosures of this kind are generally associated with early medieval settlement in Ireland, often the remains of a ringfort, a type of farmstead enclosed by an earthen bank and ditch that was common between roughly the fifth and twelfth centuries. Whether that is what lies here has not been confirmed, and the site remains a possibility rather than a certainty. It was brought to wider attention by Anna Evans, with the record compiled in August 2021.