What survives is the ghost of a cashel, a type of ringfort built from drystone walling rather than earthen banks, its perimeter now little more than a low, grassed-over ridge tracing an oval roughly 45 metres east to west and 32 metres north to south. A later field wall cuts straight through the monument at the north-north-east and south-south-west, the kind of pragmatic reuse that has quietly erased or bisected countless early medieval enclosures across the Irish countryside.

What lifts this particular ruin out of the ordinary is what lies within it. In the north-east quadrant of the interior, a children's burial ground is still visible, a cillín in local tradition, where infants who died unbaptised were interred in unconsecrated ground, apart from the parish cemetery. The practice reflects centuries of theological constraint and the grief it produced, and cilліní are found across Ireland, often tucked into prehistoric or early Christian enclosures whose marginal sacred status made them seem appropriate for those excluded from formal burial rites. In the heavily overgrown north-west quadrant, the remains of a house site add another layer to the story, suggesting that the old cashel continued to shape how people used and understood the land long after its original function had faded. A second ringfort stands some 230 metres to the south-south-west, hinting that this part of Knockdoebeg was once a more densely settled early medieval landscape than its present quiet fields suggest.