To a casual eye it might read as a natural rise in the land, but the material it is made of tells a different story. This is a fulacht fia, a type of prehistoric cooking or heating site found in extraordinary numbers across Ireland, and one of the more substantial examples recorded in West Cork.

Fulachtaí fia, found by the thousands throughout the Irish countryside, are generally understood to be the remains of ancient outdoor cooking places, though scholars have also proposed uses ranging from textile processing to brewing. The typical method involved heating stones in a fire, then dropping them into a water-filled trough to bring it to a boil. The stones, cracked and spent after repeated heating, were discarded into a mound beside the trough. Over centuries of use, those discards accumulated into the dark, horseshoe-shaped or circular mounds that survive today. The example at Kilfinnan follows this pattern, its burnt material heaped into a form substantial enough to be conspicuous in the landscape. A stream runs to the south of the site, which is consistent with the typical siting of these monuments close to a reliable water source.