At Coolnatullagh in County Clare, what survives of this prehistoric stone mound measures roughly ten metres east to west and just over five metres north to south, its southern portion having been removed at some point, leaving a truncated structure sitting on bare limestone pavement amid rough grazing. What remains is carefully constructed, the small stones held in place by thin flags laid flat and occasionally upright as revetments, a technique that speaks to deliberate building rather than casual piling.

The cairn sits within an ancient field system and lies around thirty metres to the south-east of a second cairn, which it overlooks across a gently sloping ground. A third cairn, some two hundred metres to the south, offers the clearest window into what these monuments may represent. That southern example was partially excavated and found to contain burials dating to the Chalcolithic and the Early Bronze Age, a span roughly covering the late third and early second millennia BC. The Chalcolithic, sometimes called the Copper Age, marks the transitional period in Ireland when communities were beginning to work metal for the first time, before bronze became widespread. The Coolnatullagh cairn shares a similar form to that excavated example, which suggests it may belong to the same tradition of funerary monument building, even if no excavation has yet confirmed what, if anything, lies beneath its surviving stones.