A fulacht fia, to give the feature its Irish name, is a type of outdoor cooking place common across prehistoric Ireland, typically consisting of a water-filled trough and a nearby fire used to heat stones, which were then dropped into the trough to bring the water to a boil. The spent stones, cracked and blackened by thermal shock, were piled to one side, and it is these distinctive horseshoe-shaped mounds of burnt material that survive in the landscape today.

This particular site was excavated in 1982 and 1983 by Lehane, ahead of drainage works that would otherwise have destroyed it. Before a spade went in, the site presented as a horseshoe-shaped mound; once the turf was stripped back, it resolved into a roughly circular spread of burnt material approximately eleven metres across, with a slight depression at its centre. That depression concealed a rectangular, plank-built trough measuring 1.85 metres by 0.7 metres, set into a pit that had been partially backfilled to hold it steady. Parts of the floor and side planks were well preserved. Beneath layers of mound material and a hard band of cemented buff clay, the base of the trough was packed with fire-shattered stones in a blue-black clay loam. A cluster of stake-holes along the north-western edge of the pit was tentatively interpreted as evidence for racks used to hang meat. Radiocarbon dating of timber from one of the side planks returned a date of 3850 plus or minus 30 years before present, placing the trough's construction somewhere around 1900 BC. The mound of burnt material was still visible when the site was inspected in 1986. What makes Ballyclogh particularly striking is not this single site in isolation but the fact that nine further fulachtaí fia lie within roughly 270 metres of it, ranging from 30 metres to the north-east to 270 metres to the north-north-west. Whether this reflects repeated seasonal activity, a community of related households, or something else entirely, the archaeology does not yet say.