This is a fulacht fia, a type of site found widely across Ireland and generally understood as a Bronze Age cooking place, though brewing, bathing, and textile processing have all been proposed as uses. The method involved heating stones in a fire and dropping them into a water-filled trough until the temperature rose enough to serve whatever purpose was intended. The stones, cracked and blackened by the process, were discarded into a mound nearby, and it is precisely that accumulated debris which survives today as a low horseshoe-shaped rise in the ground.

This particular example is penannular in form, meaning its mound forms almost but not quite a complete ring, open to the south-east across a gap of around eight metres. The mound itself measures roughly twenty metres north to south and nearly eighteen metres east to west, rising only about forty centimetres above the surrounding ground. A smaller break in the mound, about one and a half metres wide, sits to the north-north-east. What makes the setting especially notable is its immediate context: a standing stone lies just to the east, and a second fulacht fia sits a short distance to the south-south-east. The proximity of a standing stone and a second cooking site of the same type suggests this part of Caherbarnagh was a place of some repeated or sustained activity in prehistory, though the precise relationship between the three monuments is not recorded.