It measures eleven metres long, nineteen metres wide, and just over a metre high, and it is composed almost entirely of burnt and fire-cracked stone. This is a fulacht fia, a type of prehistoric cooking site found in large numbers across Ireland, typically beside water and on soft, boggy ground. The usual interpretation is that stones were heated in a fire, dropped into a water-filled trough to bring it to a boil, and used to cook meat. The marshy setting here is entirely characteristic.

What makes this particular site quietly notable is not the mound itself but its immediate context. Two further fulachta fiadh lie directly to the east, making this one point in a close cluster of three. Whether they were used simultaneously, seasonally, or across different periods is unknown, but their proximity suggests this stretch of the Rylane River was a place people returned to repeatedly. Fulachta fiadh are generally dated to the Bronze Age, roughly 1500 to 500 BC, though some have yielded earlier or later dates on excavation. The sheer density of them across the Irish landscape, tens of thousands have been recorded nationally, points to an activity that was both commonplace and highly organised, requiring reliable water sources and an ongoing supply of suitable stone.