It is easy to mistake for a natural rise in the ground, but the burnt material packed into that 1.8-metre heap gives it away as something far older and more deliberate. This is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, and one of the more enduring puzzles of the archaeological landscape.

Fulachtaí fia, the plural form, are typically Bronze Age in date, though some may be older or later. The basic principle is well understood: a trough was dug close to a water source, lined to hold liquid, and filled with water. Stones were heated in a nearby fire and dropped into the trough to bring the water to a boil, then used for cooking meat, and possibly for other purposes including bathing or textile processing. The crescent or horseshoe-shaped mound that survives at so many sites is simply the accumulated debris of those shattered, heat-cracked stones, discarded over repeated use. At Barrafohona, the stream to the east would have provided the essential water supply, and the central depression in the mound is the ghost of that original trough, now waterlogged and sunken but still legible in the ground.