What looks like an ordinary earth and stone division between the townlands of Killerk North and Jossestown is, on closer inspection, the surviving bank of an ancient enclosure, quietly folded into the agricultural landscape and mistaken, at least by one earlier account, for something entirely gone. Cahill, writing in 1982, described the monument as levelled. The earthworks tell a different story.

The site sits on a gentle west-facing slope in pasture, its roughly circular form measuring about fifteen metres in diameter. An enclosure of this kind, a defined area ringed by a bank and a fosse (a defensive or boundary ditch cut into the ground), belongs to a broad family of early medieval earthworks found across Ireland, related to but distinct from the more familiar ringfort. Here the fosse reaches over six metres wide and just over a metre deep on the north-east to south-west arc, while traces of an in-filled fosse continue round the western and northern sides. The intervening bank, standing nearly two and a half metres high on its exterior face, is the section that has been absorbed into the modern field boundary, which is why it has survived at all. Four shallow depressions along the south-east exterior are the remains of disused quarries, suggesting the site has been drawn on for building material at various points. Within 150 metres in either direction sit two related monuments, another enclosure to the north-north-west and a ringfort to the south-east, hinting that this was once a more populated corner of the landscape than the current pasture suggests.

The interior is described as generally level but heavily overgrown, and access has been further complicated by the dumping of fir trees inside the enclosure. The best-preserved stretches of bank and fosse run along the east and south, where the earthworks have benefited from their incorporation into the townland boundary.