These horseshoe-shaped mounds of burnt and shattered stone, typically found beside a stream or boggy ground, are generally dated to the Bronze Age, roughly 1500 to 500 BC. The name, loosely translated as "wild deer cooking place," reflects one long-held theory about their function, though archaeologists continue to debate whether they served primarily as cooking sites, as places for bathing or textile processing, or for some combination of purposes. The working method, in any version of the theory, involved heating stones in a fire until they were near-white, then dropping them into a water-filled trough to bring the water rapidly to a boil or a useful temperature. Repeated heating and quenching causes stone to fracture, and it is the accumulated debris of this process that forms the distinctive mound visible today.

The example recorded at Baile Uí Uaithnín, in County Kerry, sits within a county that contains a remarkable concentration of prehistoric monument types, from wedge tombs on the uplands to ogham stones, the earliest form of written Irish, found built into field boundaries and church sites across the Iveragh and Dingle peninsulas. Kerry's landscape, shaped by glaciation and subsequent blanket bog formation, has preserved many such features beneath layers of peat, which accounts both for the frequency of discovery and for the often excellent condition of the underlying timbers and troughs when sites are excavated. Baile Uí Uaithnín, as a placename, reflects the Gaelic naming tradition of identifying townlands by family association, in this case connected to the Uí Uaithnín lineage, though the fulacht fia itself predates any such naming by well over two millennia.