The site at Coolmeen is a cashel, the Irish term for a ringfort built primarily from stone rather than earthen banks, and roughly circular in plan at about 22 metres across. What makes it quietly compelling is not the structure alone but what has been added to and around it over time, a palimpsest of later walls, enclosures, and an unresolved mound that together suggest this was never simply abandoned and forgotten.

The cashel is defined by a bank of stone and earth, between half a metre and two and a half metres wide, with an exterior height that reaches up to 1.6 metres in places. The outer facing of the wall is best preserved on the northern to north-eastern arc and again between the south-east and south-west, while the western portion has been scarped away, possibly robbed for later building material or simply worn down. The interior is level. At the western side, two rectangular walled enclosures were added later, their dimensions carefully recorded at roughly 8.9 by 6.9 metres and 8.5 by 5.4 metres respectively; these are the kind of small field or yard divisions that speak to agricultural reuse long after the original enclosure fell out of its primary function. A further wall follows the perimeter, and just outside the cashel to the south-south-east there is a cairn or low structure standing about 1.5 metres high, its purpose uncertain. The whole site sits within a wider multiperiod field system, meaning the surrounding landscape preserves its own layered record of land division and use. The site was recorded on the Ordnance Survey six-inch map of 1915, which places it at least within living memory of documentation, though the cashel itself is considerably older.