The older cairn, roughly circular and about six metres across but only thirty centimetres high, is built of compact stones and has the appearance of considerable age. Atop it, a second cairn of looser stones was added more recently, and from its centre a concrete triangulation pillar, used by Ordnance Survey teams to map the landscape, rises to about head height. The combination is quietly odd: a prehistoric or early monument conscripted into the service of modern cartography.

What gives the site an additional layer of strangeness is something that is no longer there. Writing in 1987, a researcher named Hayward recorded three crosses formed of flat stones lying on the ground beside the cairn, and noted that these were said to mark burials. No trace of those crosses can now be found. Whether they were disturbed, buried under peat, or simply dispersed is unclear, but their disappearance leaves open a question about the cairn's original character. A cairn, in this context, is essentially a mound of piled stones, a form used across many centuries in Ireland for purposes ranging from burial to boundary marking to commemoration. The association with crosses and reputed burials hints at a site that accumulated meaning over a long period, though nothing visible on the surface today confirms the nature of those burials or their age.

Mangerton Mountain is reached from the Killarney area, and the summit, while boggy underfoot, is accessible on foot. The cairn sits at the highest point, surrounded by open upland with views extending in all directions across the Kerry landscape.