It is a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, typically identified by that characteristic horseshoe-shaped spread of burnt and shattered stone. The mound here measures roughly eleven metres in length, seven metres wide, and only half a metre high, the accumulated debris of repeated episodes of stone-boiling, in which rocks were heated in a fire and dropped into a water-filled trough to bring the contents to cooking temperature.

What gives this particular site a quiet added interest is its proximity to a second fulacht fia, recorded about a hundred and twenty metres to the south-east. Whether the two were ever in use at the same time, or represent separate periods of activity at a location that was simply well-suited to the purpose, the notes do not say. The closeness to a stream is entirely typical; a reliable water source was a practical necessity for the whole process, and fulachtaí fia are very often found near rivers or boggy ground. The burnt mound at Ballynaboul is consistent in its modest dimensions with many others recorded across County Cork, where such sites survive in large numbers, often overlooked in fields that have never been ploughed deeply enough to erase them entirely.