No mound, no hollow, no scatter of burnt stone breaks the surface. And yet, according to a 1938 Ordnance Survey six-inch map, this precise spot was already being labelled as a site of something that had long since vanished, a fulacht fia, noted with the cautious past tense the cartographers reserved for things they could record but not see.

A fulacht fia is a type of prehistoric cooking site found across Ireland in considerable numbers, typically identified by a horseshoe-shaped mound of fire-cracked stones beside a trough, often in low-lying or waterlogged ground near a water source. The method involved heating stones in a fire and dropping them into a water-filled trough to bring it to a boil, leaving behind the shattered, heat-damaged stones that form the characteristic mound. The Shanavagha example sits to the north-west of a spring, which fits the pattern precisely: these sites almost always cluster near reliable water. The marshy ground here would have preserved the organic material associated with such a site for millennia, even as it eventually swallowed any surface trace entirely.