A ringfort is a roughly circular enclosure, typically earthen, used as a farmstead during the early medieval period in Ireland, and thousands survive across the country in varying states of repair. This one does not survive at all, at least not above ground. No earthwork, no bank, no ditch remains visible to the eye. What remains is a mark on a map.

The first edition of the Ordnance Survey six-inch map recorded a circular enclosure roughly 45 metres in diameter at Ardagh, already compromised at that point by a road cutting through it at both the north-west and the east. The road did not merely clip the edge; it interrupted the enclosure at two separate points, suggesting either that a pre-existing track was formalised during the early nineteenth century, or that road improvements were simply laid down without particular concern for what lay beneath. By the time anyone thought to record what was left on the ground, the surface trace had gone entirely.