A fulacht fia is a prehistoric cooking site, typically consisting of a trough dug into the ground, a hearth for heating stones, and a mound of the shattered, burnt material that accumulated as the stones were repeatedly fired, dropped into water to bring it to the boil, and discarded when they cracked. Thousands of these sites survive across Ireland, most dating to the Bronze Age, and yet the precise social context of their use, whether for cooking, bathing, brewing, or some combination, remains a matter of ongoing debate among archaeologists.

The mound at Carriganimmy now measures about eight metres in length, three and a half metres wide, and stands roughly seventy centimetres high, though what survives is only a partial record. The bulk of the original mound appears to have been removed, most likely during drainage work in the area, a fate that has befallen countless similar sites across the country as low-lying and waterside land was improved over the centuries. The loss is legible in the landscape: burnt material is still visible eroding from the bank of the adjacent stream, and further deposits have been identified nearby, scattered during whatever activity disturbed the site. What remains is essentially the western arc of what was once a larger horseshoe-shaped accumulation, the classic form these monuments take when they survive intact.