The site is a fulacht fia, a type of ancient outdoor cooking place found in enormous numbers across Ireland, typically beside a water source. The basic method involved heating stones in a fire, then dropping them into a water-filled trough to bring it to a boil, a process that eventually leaves behind a characteristic mound of fire-cracked, blackened stone. Thousands of these sites are known across the country, most dating to the Bronze Age, though some were used into the early medieval period.

This particular example was identified in April 1993 by Triona Buckley of University College Cork, who noted a spread of burnt material measuring roughly 15 metres by 20 metres lying in tillage ground to the north of a stream. The proximity to running water is typical; a reliable water source was essential to the whole process, and fulachta fia are almost invariably found close to rivers, streams, or marshy ground. The spread of burnt and broken stone that Buckley recorded is the physical signature left by repeated heating and quenching cycles over what may have been a very long period of use. What lies beneath the surface in Killeen, whether a timber-lined trough, associated features, or stratified deposits, remains unexcavated and unknown.