A fulacht fia, the term given to the horseshoe-shaped mounds of burnt and shattered stone found across Ireland from the Bronze Age onwards, was once visible here as a mound. The typical fulacht fia worked by heating stones in a fire and dropping them into a water-filled trough until the water boiled, a method capable of cooking large quantities of meat. At Knockcloona, even that low earthen profile has since been lost to ploughing.

The mound was recorded on a 1937 Ordnance Survey six-inch map, which means it was still a legible feature in the landscape within living memory. At some point between that survey and the present, tillage farming levelled it entirely, leaving no visible surface trace. The site's proximity to a spring is entirely characteristic. Fulachtaí fia are almost always found close to a reliable water source, whether a stream, a bog, or, as here, a spring, since the whole process depended on a ready supply of water. That spatial logic is one of the reasons such sites survive in the record even when the physical monument itself is gone.