What draws the eye, once you know to look, are the four distinct piles of stones rising from its surface. Two of them are narrow, steep-sided, and taper to a point, each roughly 1.3 metres tall and only 0.6 metres wide, constructed apparently from material taken from the cairn itself. The other two are broader, lower, and less sharply defined. The whole structure measures around fifteen metres in diameter but barely reaches 0.6 metres in height, which gives it the quiet, half-buried quality of something the landscape has been slowly reclaiming.

Local memory has preserved a name for the site: Lacht an Phelim, meaning roughly the cairn or memorial heap of Phelim, a reference to Phelim O'Dolan, recorded as an ancient proprietor of Gleann Gaibhle, the valley now known as Glangevlin in the uplands of south-west Cavan. A cairn in this context is simply a deliberate mound of stones, used across Irish history as a boundary marker, a memorial, or both. The authors of The Kingdom of Glan, a local history published by the Glangevlin Guild of the Irish Countrywomen's Association in 1983, noted that it was erected some centuries ago, which is precise enough to suggest genuine tradition without being precise enough to pin down a date. That the site went unrecorded by nineteenth-century surveyors is itself curious, since boundary features were generally of interest to the Ordnance Survey; its absence may suggest it was already obscure, or simply that it sat in terrain the surveyors passed over quickly.