On a south-facing slope in the upper Tay river valley, in the uplands of the Comeragh Mountains, there is a low grass-covered mound that most walkers would pass without a second glance. It is kidney-shaped, roughly 14 metres by 9 metres, and rises no more than 0.8 metres at its highest point. Beneath the turf, however, the mound is composed entirely of broken and fire-cracked stone, and that detail changes everything about how you read the landscape around it.

This is a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, typically dating from the Bronze Age. The basic principle involves heating stones in a fire, then dropping them into a water-filled trough to bring it rapidly to the boil. The stones crack and shatter with repeated heating and cooling, and over time the discarded fragments accumulate into the characteristic horseshoe or kidney-shaped mound that survives today. The site on Comeraghmountain follows this form closely, opening to the north-east, which is where the trough would originally have sat. Whether fulachta fiadh were used primarily for cooking meat, for textile processing, or for bathing remains a subject of genuine debate among archaeologists, and the honest answer is probably that different sites served different purposes at different times.