It measures roughly thirteen metres east to west and ten metres north to south, and beneath its turf covering lies a spread of burnt material that marks it out as something far older and more deliberate than a simple earthwork.

This is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, with County Cork containing a particularly dense concentration of them. The typical fulacht fia consists of a horseshoe-shaped mound of fire-cracked stone and charcoal, the accumulated debris of repeated use, usually positioned close to a water source. The working method, as archaeologists have reconstructed it, involved heating stones in a fire and dropping them into a water-filled trough to bring the water to boiling point, cooking meat or other foodstuffs in the process. The cracked and spent stones were then discarded to the side, building up over time into the distinctive mound that survives today. The proximity of the Gort An Acra example to a stream fits this pattern precisely, since a reliable water supply was essential to the whole process. Most fulachtaí fia date to the Bronze Age, roughly between 1500 and 500 BC, though some have produced earlier or later dates.