It measures about six and a half metres long, fourteen metres wide, and two metres high, which makes it a fairly substantial presence in the landscape even after millennia of settling and, apparently, some disturbance from road building. There is nothing about it that would announce itself to a passing eye, yet it represents one of the most common and least understood monument types in the Irish archaeological record.

A fulacht fia, sometimes called a burnt mound, is the remains of an ancient outdoor cooking or processing site. The typical method involved heating stones in a fire and then dropping them into a water-filled trough to bring the water to a boil. The cracked and shattered stones, blackened by repeated heating, were raked out and piled nearby after each use, and over time those discarded heaps built up into the horseshoe-shaped or irregular mounds that survive today. The Killacloyne example is described as irregular in shape, which may reflect that road construction has disturbed part of the original deposit. These sites are generally associated with the Bronze Age, though the exact purposes they served, whether cooking, bathing, textile processing, or some combination, remains a subject of ongoing discussion among archaeologists. They are found in their thousands across Ireland, almost always near water, and this one follows that pattern precisely, positioned beside a stream that would have supplied the essential raw material for the whole operation.