The ground above it looks like ordinary pasture. Nothing breaks the surface, no mound, no depression, no scatter of burnt stone to catch the eye of a passing walker. The only document that ever marked it with confidence was an Ordnance Survey map from 1937, which recorded a mound at this location. By the time anyone thought to check, the mound had gone.

A fulacht fia is a type of site found in enormous numbers across Ireland, particularly in low-lying or waterlogged ground. The basic principle involves a trough, usually timber-lined or stone-lined and sunk into the earth, filled with water, which was then heated by dropping fire-cracked stones into it. The shattered, burnt stones accumulated over time into the characteristic horseshoe-shaped mound that identifies these sites from the air or on foot. They date mostly to the Bronze Age, though some were used into the early medieval period, and their purpose has been debated for generations; cooking is the most widely accepted explanation, though brewing, hide-working, and bathing have all been proposed. The Knockskehy example fits a familiar pattern: a low mound recorded on a mid-twentieth-century map, situated in marginal agricultural land, and now reduced to nothing visible at ground level. Ploughing, drainage work, or simple erosion can erase these features entirely, leaving only the cartographic record as evidence that something was once there.