Cropmarks form when buried features such as ditches or walls affect the growth of crops above them, producing colour or height differences that become legible in aerial photographs. That is exactly how this enclosure came to light, detected in Digital Globe imagery rather than through any ground-level investigation. What makes it genuinely curious is that nobody is quite certain what it is, or even when it was made.

The first edition Ordnance Survey six-inch map does not record it as an antiquity, which might suggest it post-dates the early nineteenth century, or simply that whoever drew the map did not recognise it as such. The 1910 edition of the twenty-five-inch OS map does, however, show a trigonometric station at this location, marking a spot height of 491 feet above ordnance datum. Trig stations were the fixed reference points used by the Ordnance Survey to build its network of triangulated measurements across Ireland, and they were often placed on elevated or otherwise commanding ground. The circular enclosure may have been constructed by the Ordnance Survey itself to shelter or define that station, which would make it a post-1700 feature of entirely practical origin. There is, though, another possibility: that an older archaeological enclosure, perhaps a ringfort or similar early medieval structure, was already present on the ground and was simply reused by the surveyors as a convenient and ready-made boundary. The aerial evidence alone cannot settle the question, and without excavation or further survey the site sits in an unresolved state, part administrative infrastructure, part potential antiquity.