That scatter is what remains of a fulacht fia, a type of ancient cooking or heating site found in extraordinary numbers across Ireland, typically Bronze Age in origin, and usually identified by the characteristic blackened, shattered stones that result from repeatedly heating rocks and plunging them into water-filled troughs.

When the site was recorded, the landowner, a Mr O'Leary, noted that the shattered stones had stood roughly a metre in height, suggesting the mound was still reasonably intact within living memory. By the time of C. Toal's North Kerry Archaeological Survey, published in 1995, that mound had disappeared entirely, leaving only the spread of burnt material. The loss of the raised form is not unusual; fulachta fia are among the most vulnerable of Irish monument types, easily levelled by agricultural activity or simply by the gradual movement of material down a slope. What the hill at Fortwilliam now holds is, in a sense, the residue of repeated ancient activity rather than a monument in any conventional sense.