No earthwork rises from the surface, no bank breaks the horizon. The only way to know it is there at all is to look down from the air, or to consult an Ordnance Survey map drawn before the feature disappeared from view.

The first edition six-inch OS map of 1839 recorded it clearly as a rectangular enclosure, orientated roughly northeast to southwest, with its sides widening towards the southwest. By the 1900 revision it was already appearing as an unenclosed rectangular area, suggesting the physical boundaries had by then been levelled or worn away. What survives is a fosse, the ditch that once defined the perimeter, now buried beneath the soil. A fosse of this kind, dug to delineate or defend a bounded space, is the diagnostic feature of any number of enclosure types in Ireland, from early medieval farmsteads to more formal ecclesiastical or settlement sites. The specific function of this one is not recorded. Its dimensions, roughly 26 metres north-northwest to south-southeast and 22 metres east-southeast to west-northwest, are modest, suggesting a relatively small enclosed space rather than a large defended compound. Aerial photographs taken in July 2000 and satellite imagery examined in 2019 both show it as a cropmark, the kind of faint discolouration in growing vegetation that appears when buried ditches or foundations alter the moisture and nutrient content of the soil above them, making the buried outline legible from altitude in a way that ground-level inspection never could.