This is a cashel, the Irish variant of a ringfort built from dry-stone rather than earthen banks, and the example at Cill Ráine has reached a stage where its original stonework is almost entirely obscured. No wall-facing survives to the eye, no obvious entrance gap remains, and the collapsed material fans out most heavily on the external face, suggesting centuries of slow outward slippage rather than deliberate demolition.

The cashel is roughly subcircular, measuring approximately forty metres east to west and thirty-five metres north to south internally, dimensions that place it at a respectable scale for a site of this type. Cashels like this were typically built during the early medieval period as enclosed farmsteads, the stone walls serving the same defensive and territorial function as the earthen raths more common in the eastern and midland counties. What makes this one quietly interesting is the internal topography. The western half of the interior sits roughly a metre higher than the eastern half, a difference marked by what appears to be a grassed-over stony spread indicating a possible internal dividing wall. Such subdivisions are known in cashels elsewhere and may reflect separate functional areas within the enclosure, though here the feature is tentative rather than certain. The entire site is overgrown with bramble, briars, hazel, and ferns, and sits within what was until recently a mature tree plantation; the trees immediately around and within the cashel have been felled, leaving a scatter of stumps across the already uneven interior.