The site is a cashel, the Irish term for a ringfort defined by a stone rather than earthen boundary, and what survives above ground today is modest: a roughly circular enclosure, about nineteen metres across, bounded by a ruined wall that now stands less than a metre high and a metre and a half wide. Large boulders to the north-east still hint at the original construction method, with inner and outer stone faces packed around a rubble core. Elsewhere, a later wall was simply laid along the line of the old cashel boundary to the north-west, borrowing its course the way farmers across Ireland have always recycled older structures rather than work around them.

The more intriguing element here lies underground. A souterrain, which is a deliberately constructed underground passage or chamber typically built from drystone walling and large capstones, runs beneath the interior of the enclosure. Souterrains are found across early medieval Ireland, most often associated with ringforts dating from roughly the sixth to the twelfth centuries, and their precise function is still debated. Storage of perishables, refuge during raids, and simple drainage have all been proposed at various sites; in many cases they probably served more than one purpose at different times. The souterrain at Cooldurragha carries its own separate monument record, suggesting it was substantial enough to be catalogued independently from the cashel that contains it.

The site sits on a break in a south-east-facing slope, the kind of position early farmers chose deliberately for shelter, drainage, and a clear view of the surrounding land. Overgrowth now obscures much of the walling, and nothing about the field surface announces what lies beneath it.