These horseshoe-shaped mounds, typically formed from heat-shattered stones and charcoal-darkened soil, are thought to represent ancient cooking sites, where water was boiled by dropping fire-heated stones into troughs. The example at Carrigrohane, on the edge of a marshy area in County Cork, conformed closely to the type: a low, grass-covered mound roughly ten metres east to west and eight metres north to south, rising only about thirty centimetres above the surrounding pasture, with its characteristic opening, around two metres wide, facing south-west.

The site came to light in a more systematic way in 1995, when it was recorded sitting beside a drain at the margin of boggy ground, exactly the kind of damp, water-adjacent location where fulachtaí fia most often appear. It might have remained simply a note in a county inventory had the route of the Ballincollig Bypass not passed directly through it. Excavation followed in 2001, and the findings were a mixture of the informative and the frustrating. Ploughing had badly disturbed the mound, with furrow marks cutting down into the natural subsoil beneath. Underneath the surviving material, however, archaeologists uncovered four roughly circular pits that may originally have served as the water-filled troughs central to the site's function, the containers into which heated stones were plunged to bring water to the boil. The bypass that prompted the excavation has long since been built, and the site itself no longer exists in any accessible form.