Field walls have been built directly over the remains, running across the northern to eastern arc and again from the south-east through the west and back to the north, so that what was once a coherent defensive perimeter has been quietly cannibalised by centuries of agricultural reorganisation. A stand of trees has taken hold in the north-eastern quarter of the interior, which gives that corner a rather different character to the rest.

The structure is a cashel, a type of ringfort built from drystone rather than earthen banks, and this one measures roughly 41.5 metres in diameter. Cashels are among the most common monument types in the Irish landscape, dating broadly to the early medieval period, roughly 500 to 1000 AD, and were typically used as enclosed farmsteads rather than purely military fortifications. This example lies some 270 metres south-east of a second ringfort, suggesting that the broader area around Cahernaglass once supported a more concentrated pattern of settlement than the present countryside might imply. The two sites in proximity, though unconnected by any surviving physical link, point to a landscape that was once meaningfully organised rather than sparsely occupied.