Beneath the turf lies a scatter of burnt material, the characteristic residue of a fulacht fia, and where the well cuts through the earth at its southern side, that same scorched and shattered stone is visible in section, exposed as though the landscape is offering a small footnote to itself.

A fulacht fia is a type of burnt mound found widely across Ireland, typically dating to the Bronze Age. The standard interpretation holds that they were cooking sites, where stones were heated in a fire and then dropped into a water-filled trough to bring it to a boil. Over repeated use, the cracked and spent stones accumulated into the horseshoe-shaped mounds that survive in fields and bogs across the country. The Knockawillin example sits adjacent to a well, which fits the pattern well; proximity to a reliable water source was essential to the whole operation. What makes this particular site quietly notable is the detail preserved in local memory: according to people who knew the land, the mound had already been levelled before 1954, flattened at some point during the mid-twentieth century in the course of ordinary agricultural life. The burnt material visible in the well section is, in a sense, what escaped that levelling.