It is roughly twenty metres across, circular in plan, and easy to miss if you do not know to look for it. What makes it worth a second glance is not its scale but its detail: a proper entrance at the south-east, framed by three upright stone slabs, two on the east side and one on the west, still standing to nearly a metre in height. That kind of deliberate threshold-making, stones set on end to define a passage rather than simply left as rubble, suggests this was once a managed and meaningful space rather than a casual fold thrown up against the weather.

An enclosure of this type, a roughly circular area defined by a stone and earth wall, is a form that appears repeatedly across the Irish uplands and can belong to almost any period from the early medieval onwards. Here on Knockbrack, the picture is made more readable by what surrounds it. Inside the enclosure, abutting the south-east arc, is an oval stone-walled hut site, its entrance aligning with the main entrance so that someone passing through the outer gateway would have arrived directly at the door of the inner structure. Beyond the enclosure wall, relict field boundaries spread outward across the hillside, and two of those old field walls connect directly to the enclosure at the north and south. The whole arrangement reads as a small agricultural landscape that was once coherent and inhabited, even if the details of when and by whom remain unresolved. The 1895 Ordnance Survey six-inch map recorded the oval area and noted a roughly square sheepfold abutting the south-east arc internally, suggesting that whatever the site's origins, it was still being put to practical pastoral use in the nineteenth century.

The site sits in rough upland pasture, covered in overgrowth, and the wall survives best along the south-east to west arc. The entrance slabs are the clearest structural feature remaining and the most rewarding thing to examine closely on the ground.