This is a cashel, a type of ringfort defined by a stone rather than an earthen boundary wall, and the one at Clooneen is large enough that its surviving wall faces run in what appear to be straight lines, an unusual visual effect produced simply by the scale of the enclosure. Most ringforts read as clearly curved from any vantage point, but here the arc is so wide that sections of the perimeter look almost rectilinear.

The wall itself survives as a spread of stone between four and seven and a half metres wide, standing internally to about a metre in height and reaching nearly two metres on the outer face in places. Two stretches of original facing remain legible, one on the north-west and one on the north-north-east, each running for around ten metres and built from large stones roughly a metre long and half a metre wide. Inside, the site preserves a layered complexity that suggests it was used and perhaps modified over time. A subsidiary enclosure occupies the southern interior, and three possible hut sites are arranged around the inner edge of the perimeter wall, positioned at the north-west, south-south-west, and west. The cashel also sits within what appears to have been a much broader pattern of land use, an extensive field system spreading across the surrounding area, which points to a farmed and organised landscape rather than an isolated structure.