Oval and flat-topped, its core measures roughly 12 metres by 10 metres and still stands nearly two metres high at its south-eastern edge. Collapsed material has spread outward on almost every side, giving the whole structure an overall spread of around 16 metres across. What has not tumbled away is largely buried under a thin crust of peat. A shallow depression near the north-eastern edge hints at something beneath, perhaps a disturbed burial chamber, though the cairn has not been formally excavated. Fragments of rough stone facing survive at the south-west, suggesting the mound was once more deliberately shaped than it now appears.

The summit position is not accidental. Cairns of this kind were frequently placed on high, visible ground, and whoever chose this spot had a sharp eye for sightlines. On a clear day the view opens northwest towards Castlemaine Harbour and southeast to Lough Leane, the largest of the Killarney lakes, though the surrounding mountains close off other directions entirely. A circular dry-stone shelter, 2.6 metres in diameter, sits just to the north-west of the main mound, possibly built by later generations making use of the ready-cut stone. A second cairn lies nearby, and together the two may be the 'sepulchral heaps of stone near each other on the summit of Tomies mountain' described by the writer and historian M. F. Cusack in 1871, suggesting the site was already being noted, if not fully understood, well before modern archaeological surveying reached this corner of Kerry.