It is a fulacht fia, a type of prehistoric cooking site found in great numbers across Ireland, typically identified by a crescent or horseshoe-shaped mound of burnt and shattered stone left over from repeated heating. The mound here rises to about 0.8 metres, with its opening, measuring roughly 5.8 metres north to south and 3.2 metres east to west, facing east. A spring lies close by to the north-east, which is exactly the kind of water source these sites consistently required.

The standard interpretation of fulachtaí fia is that they functioned as outdoor cooking places, most likely during the Bronze Age. Water was drawn into a trough, usually timber-lined, and stones were heated in a nearby fire before being dropped into the water to bring it to boiling point. The process was repeated until the food, typically wrapped meat, was cooked. The discarded, heat-cracked stones accumulated over time into the distinctive mound that survives. The Ballyhubbo example follows this pattern closely, sited beside a natural spring and built up from successive layers of fire-shattered material. Its southern section and part of the western arc have been lost or absorbed into field fences at some point, which is a common fate for monuments that sit at the margins of later agricultural boundaries.