Most were built between roughly the fifth and twelfth centuries, and several tens of thousands survive across the country in varying states of preservation. The example at Kilnadur in County Cork is modest but quietly instructive, precisely because the engineering logic of its construction is still legible in the ground itself.

Situated on a south-west-facing slope, this circular enclosure measures about 25 metres in diameter, surrounded by an earthen bank that reaches roughly 1.1 metres in height along its north-to-south extent. What makes it worth a second look is the way its builders negotiated the hillside: the interior has been cut back into the slope on the northern side, while the southern side has been built up to compensate, producing a roughly level interior platform despite the gradient. A shallow external fosse, or ditch, runs along the south-eastern arc, and a scarp, a natural or engineered slope face, survives to the south-west. Gaps in the bank on both the north and south sides likely mark original entrances, a common feature of rath construction. A field fence now cuts across the north-western edge, the kind of quiet encroachment that speaks to centuries of continuous agricultural use around and over such sites.

The site sits in pasture, which is fairly typical for surviving raths in the west Cork landscape. Grazing land has often preserved earthworks that would long since have been ploughed away under tillage, so the fact that cattle rather than crops surround it here may be one reason it survives at all.