The one at Shinnagh in County Mayo is a quiet example of a type that continues to puzzle archaeologists. A fulacht fia, in its simplest form, is a burnt mound, typically a horseshoe-shaped heap of heat-shattered stone and dark, charred earth sitting beside a trough or pit. The working theory, broadly accepted though not without its dissenters, is that these sites were used for cooking, most likely by heating stones in a fire and dropping them into a water-filled trough to bring it to boiling point. The characteristic crescent of blackened, crumbled stone is what tends to survive.

These sites cluster heavily in low-lying, often boggy ground, which is partly why they are so frequently preserved and partly why they are so frequently overlooked. Most date to the Bronze Age, roughly between 1500 and 500 BC, though some have produced earlier or later dates. The Shinnagh example sits within a county that has no shortage of prehistoric remains, from megalithic tombs to field systems preserved beneath blanket bog. Beyond its location and classification, the specific details of this particular monument, its dimensions, condition, and excavation history if any, remain undocumented in publicly available sources at present.