The one at Clenagh in County Clare is a quiet example of a type that appears so frequently in fields, bogs, and riverbanks that it is easy to walk past without a second thought. A fulacht fia typically survives as a low horseshoe-shaped mound, the accumulated debris of repeated heating episodes, and it is this modest silhouette that has puzzled archaeologists for generations.

The standard interpretation holds that fulachtaí fia were cooking sites, used during the Bronze Age, roughly between 1800 and 800 BC, though some examples are earlier or later. The method involved heating stones in a fire and then dropping them into a water-filled trough, bringing the water rapidly to a boil. The cracked and shattered stones, useless after a single heating, were discarded to the sides of the trough, and it is those discard heaps that form the mounds visible today. The Clenagh example sits within this broader Bronze Age tradition, one of hundreds recorded across Clare alone, a county whose boggy ground has preserved such sites with unusual consistency. Some researchers have questioned whether cooking was the only or even the primary purpose, with proposals ranging from hide processing to bathing to brewing, though none of these alternatives has displaced the cooking explanation entirely.