Somewhere in a pasture at Knockaderry, on a south-east-facing slope beside a small stream, there is a prehistoric cooking site that nobody can quite find any more. Recorded in the 1950s and filed with the National Museum of Ireland, it has since vanished from the surface of the ground entirely, its precise location lost. That a site can be officially known to exist and yet be effectively unfindable is one of the quieter puzzles of Irish archaeology.

The site in question is a fulacht fia, a type of monument found in large numbers across Ireland and typically dating to the Bronze Age. The term refers to a horseshoe-shaped mound of fire-cracked stone and charcoal-rich earth, the accumulated debris of repeated episodes of water-heating. The most widely accepted interpretation is that stones were heated in a fire and then dropped into a water-filled trough, bringing the water rapidly to a boil for cooking. The siting here follows a pattern common to fulachta fiadh across the country: close to a reliable water source, in this case a stream running west to east along the southern edge of the field. A second burnt mound, a related but formally distinct monument type, lies roughly 100 metres to the east, suggesting this corner of Knockaderry saw repeated or prolonged prehistoric activity. Whether the two sites were contemporary or separated by generations, the notes do not say.