You cannot see it by standing at the field's edge, and you would not find it by walking across it. It only reveals itself from the air, and only under the right conditions: a dry summer, when moisture stress turns the grass or crop above a buried ditch a slightly different shade, tracing out the ghost of a structure that has not been visible from the ground for a very long time. This phenomenon, known as a cropmark, is one of the primary ways archaeologists locate sites that have left no upstanding remains whatsoever.

The enclosure was identified from Google Earth imagery captured in June 2018 and recorded by Tom Condit, with the record uploaded to the national monuments database in April 2021. What the cropmarks outline is a large circular enclosure with an external diameter of approximately 39.5 metres, defined by a ditch roughly one metre wide. The western perimeter shows most clearly in the aerial imagery. Circular enclosures of this kind are common across Ireland and were used from the prehistoric period through the early medieval era, serving variously as settlement boundaries, ceremonial spaces, or enclosures for livestock. What makes this example quietly interesting is what is absent: there is no visible evidence of an entrance gap anywhere in the ditch, which would normally be expected to allow access. Whether that gap was filled in at some later point, lies on a part of the perimeter where the cropmark is less legible, or reflects something unusual about the enclosure's original design is not yet known. A small unnamed stream runs approximately 56 metres to the east, a detail consistent with the tendency of early enclosures to be sited near water sources.

The site lies in working farmland and is not publicly accessible in any formal sense. The most practical way to examine it is through Google Earth, searching in the vicinity of Lusk Round Tower and looking south-south-west across the fields. The June 2018 imagery in which the cropmarks are visible remains available through the platform's historical imagery function. The round tower itself, a prominent Early Christian structure in the village of Lusk, is the useful landmark for orienting yourself. Cropmarks of this kind are typically best captured in imagery from dry summers, so later aerial photography taken under similar conditions might reveal additional detail about the enclosure's full extent.