What they most likely represent is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, typically dating from the Bronze Age. The standard form involves a trough dug into the ground, a nearby water source, and a mound of fire-cracked stone built up over time as heated rocks were used to boil water and cook food. The burnt and shattered stone is precisely the kind of residue that shows up here.

Most fulachtaí fia survive as low, horseshoe-shaped mounds of dark, heat-fractured stone, often in wet or low-lying ground where a natural spring or stream would have provided a reliable water supply. The Cloonsillagh example appears to be a more fragmentary survival, its presence known mainly through what agricultural disturbance has turned up rather than through any visible surface feature. Local information rather than formal excavation has been the source of what little is recorded, which is itself fairly typical for the more modest examples of this site type across Cork and the wider country.