At roughly 42 metres in diameter, it is a rath, the most common type of early medieval enclosure in Ireland, typically formed by a raised earthen bank and used as a defended farmstead. What remains here is modest: a bank about two metres wide and barely 30 centimetres high, best preserved along the northern and eastern arcs, while the southern stretch has been largely flattened by generations of grazing cattle. The interior may be very slightly raised, sloping gently downward toward the south-east, though the relief is so subtle now that it takes a moment to read.

The site had already attracted notice by the 1840s, when it was described as a handsome rath that derived its name from the townland of Knockauncore, in the parish of Kilcummin. By 1846 it had been recorded on the Ordnance Survey six-inch map as a roughly circular enclosure, its bank running from south-west to east and meeting existing field boundaries on two sides. The fact that the rath had already shaped the pattern of fields around it by the time the surveyors arrived suggests a long familiarity in the landscape, the kind of feature that farmers had been working around, and occasionally trampling through, for centuries before anyone thought to write it down.