By the time a field inspection was carried out in 1998, they had vanished entirely, leaving no obvious trace. Whether robbed out, buried under encroaching material, or simply misidentified in the first instance, their disappearance is the kind of small archaeological mystery that accumulates quietly around sites like this one.

A cashel is a ringfort defined by a drystone wall rather than an earthen bank, and this example at Ballynahown sits on flat ground with higher, rockier terrain rising to the east and south-east. The structure is roughly square in plan, measuring approximately 27 metres on its longer axis and 25 metres on the shorter, which makes it a reasonably substantial enclosure of its type. The wall is largely collapsed and poorly preserved, though the eastern stretch survives best, with the outer face still readable to a height of around 1.6 metres externally and 1.8 metres on the interior side. Towards the south-west the boundary dissolves into an overgrown bank of stone and earth, thick with briars, while between the west-north-west and north-north-east it spreads into a low, broad stony bank roughly five metres wide. Westropp, writing in 1905, described the whole thing as an "irregular bawn", using the term, borrowed from plantation-era enclosures, to convey something roughly defined and not quite conforming to the tidier examples of the type. The cashel is marked on the 1915 Ordnance Survey six-inch map, which at least fixes it in the documentary record even as its physical fabric continues to erode. Agricultural reclamation of the fields to the north and east has added to the damage, with spoil and clearance material piled against the cashel's northern and eastern edges, making it increasingly difficult to read where the original structure ends and later disturbance begins. The interior retains rocky outcrops near the centre and in the south, hinting at the kind of uneven ground that may have shaped where the enclosure was placed to begin with, and from the site there are open views westward over lower ground toward the sea.