The one at Cussan, in County Kilkenny, measures somewhere between ten and twelve metres across and rises only about half a metre above the surrounding ground, but it represents a form of prehistoric activity found across Ireland in the hundreds, if not thousands. It is a fulacht fia, a type of ancient cooking or processing site typically identified by its characteristic spread of heat-shattered, fire-cracked stone, accumulated over repeated use.

The mechanics of a fulacht fia are straightforward enough: stones were heated in a fire and then dropped into a water-filled trough, bringing the water to a boil. The cracked and spent stones were discarded to the side, building up over time into the horseshoe-shaped or oval mounds that survive today. What makes the Cussan site particularly notable is that it does not sit in isolation. Two further fulachta fia lie within the same field, one approximately forty-five metres to the south-west and another around a hundred and fifteen metres in the same direction. The grouping of three within such a compact area, all on a south-facing slope in boggy ground, where a water source would have been reliably close at hand, suggests this stretch of land saw sustained and repeated use during prehistory, though precisely when is not recorded for this site.