This is a cashel, the Irish term for a ringfort defined by stone rather than earthen banks, and this one at Dooneens measures roughly 24 metres across with a surviving wall standing to about 1.2 metres in height. The combination of agricultural reuse and incremental repair has given it the slightly ambiguous quality common to many such sites, where the ancient and the recent are physically layered on top of each other.

When P. J. Hartnett recorded the site in 1939, he observed that the dry-stone rampart had been partly built up in recent years, though along the line of the original foundation. That detail matters: whoever added to the wall was following an earlier course rather than improvising, which suggests the underlying structure was still legible enough to guide them. Ringforts of this kind were typically constructed during the early medieval period, serving as enclosed farmsteads for a single family or small kin group. The stone-built variant, the cashel, is particularly associated with the more westerly and upland parts of Ireland where building stone was readily available. Within the interior at Dooneens there is also a possible souterrain, an underground passage or chamber often associated with ringforts and thought to have served for storage, refuge, or both. Whether that feature is intact or partially collapsed is not recorded in detail, but its presence would not be unusual in a site of this type and date.