The cairn at Kiltiernan measures roughly 13.5 metres across and rises just 1.3 metres above the surrounding ground, its surface long since softened by turf and composed beneath of small, well-rounded stones. What catches the attention of anyone who looks closely is the slight depression at its summit, a gentle dishing of the top that suggests the mound has been disturbed at some point, though when, by whom, and for what purpose is not recorded.

The cairn sits about 25 metres to the south-east of the enclosing wall of an ecclesiastical enclosure at Kiltiernan. That enclosure, the curved or roughly circular boundary that once defined the sacred space around an early Christian site, is a common feature in the Irish landscape, and the proximity of an older burial monument to such a site is equally familiar. Pre-Christian cairns, which are essentially stone heaps raised over a burial or as a territorial or ceremonial marker, were frequently absorbed into the sacred geography of early medieval religious communities, whether through deliberate association or simply through the slow accumulation of local significance over time. Whether this cairn predates the ecclesiastical enclosure by centuries or belongs to an entirely different tradition remains an open question.