The one at Killeens, in County Cork, has done something slightly different: it has quietly become part of the working landscape, its remains folded into the boundary system of the surrounding fields as though always intended for that purpose. A ringfort, or rath, was a roughly circular enclosure defined by earthen banks and ditches, used during the early medieval period as a farmstead and enclosure for livestock. They were built in their thousands across Ireland, and they were demolished in their thousands too, as farming practice changed and land was consolidated over the centuries.

By the time the Ordnance Survey mapped this area in 1842, the enclosure at Killeens was already recorded as a circle of roughly 38 metres in diameter on the six-inch map, a standard piece of cartographic note-taking that preserved the outline even as the physical structure was being eroded. What survives today is considerably less than that full circuit: a single arc of roughly 16 metres, formed by an earthen bank with a stone-faced revetment and standing to about 1.6 metres in height, tucked into the south-western edge of the original enclosure. That surviving fragment has been absorbed into the field fence system, so the ancient boundary and the modern one have effectively merged, with the old bank doing the same job it may have done for a thousand years or more, keeping one stretch of land separate from another on a north-facing slope of pasture.