At Clashroe in County Cork, one such site sits in marshy ground just east of a stream, presenting itself as a low, irregular mound of burnt and fire-cracked material, seven metres wide and rising to about 1.4 metres at its highest point. A shallow depression roughly two metres across and 0.3 metres deep marks what would once have been a trough, the functional heart of the whole structure.

A fulacht fia, for those unfamiliar with the term, is essentially the debris left behind by a prehistoric cooking or heating site. The typical method involved heating stones in a fire, dropping them into a water-filled trough to bring the water rapidly to the boil, and then using that heat for cooking, possibly also for bathing or textile processing. The cracked, heat-shattered stones were raked out and piled to the side after each use, which is precisely what forms the distinctive horseshoe-shaped or irregular mound visible today. What makes the Clashroe example particularly interesting is not the single site in isolation but its context: it is one of a cluster of five fulachtaí fia in the immediate area. That kind of concentration suggests sustained, repeated activity in this landscape over time, perhaps drawing on the reliable water source provided by the nearby stream and the naturally boggy ground, both of which would have made the site well suited to the purpose.