The gorge runs roughly north-east to south-west, with a rock-face forming its south-eastern wall, and an old Ordnance Survey map notes a spring about fifty metres to the south-west and flags the surrounding ground as liable to flooding. That waterlogged setting is no accident. A fulacht fia, the term for a type of prehistoric cooking or processing site found in great numbers across Ireland, almost always appears near a reliable water source. The typical method involved heating stones in a fire, then dropping them into a water-filled trough to bring the liquid to a boil. The cracked and blackened stones were then discarded into a mound around the trough, which is precisely what gives these sites their characteristic shape.

The mound at Clooncoose measures roughly fifteen metres along its longer axis and is open towards the east-south-east, enclosing a shallow concave area of about five by two metres. At the western edge of that interior, the mound has been damaged, and the exposed section reveals burnt stone and ash, offering a direct look at the accumulated debris of repeated firings. A further spread of burnt stone extends about four metres southward from the mound, either a continuation of the original deposit or material that has slipped over time. The site appeared in the Record of Monuments and Places in 1996, listed as a possible complex of more than one feature, a designation based on a map annotation made by Tom Coffey in 1994 describing it as a fulacht fiadh complex.