It is a fulacht fia, a type of prehistoric cooking site found in the hundreds across Ireland, typically consisting of a burnt-stone mound and an adjacent trough or hollow where water was heated by dropping fire-cracked stones directly into it. The process was simple and effective: stones were heated in a fire, transferred to a water-filled pit, and used to bring the water to a boil. Over time, the spent, shattered stones were raked aside and accumulated into the characteristic horseshoe or oval mound that survives today.