The one recorded at Raigh in County Mayo is a typical example of a monument type that still sparks debate among archaeologists. A fulacht fia, broadly speaking, is a Bronze Age cooking site, identifiable today as a low, horseshoe-shaped mound of burnt and shattered stone, usually found close to a water source. The standard interpretation is that stones were heated in a fire, then dropped into a water-filled trough to bring it to a boil, though alternative theories have proposed uses ranging from textile processing to bathing.

The Mayo landscape is particularly rich in prehistoric remains, and fulachtaí fia form a significant thread running through that prehistoric record. Most examples date to the Bronze Age, roughly 1500 to 500 BC, though some have produced earlier or later dates. The characteristic crescent mound forms because used, fire-cracked stone was repeatedly discarded to the sides of the trough over many episodes of use, building up over time into the shape that survives in the ground today. Their sheer number across Ireland suggests they were not occasional or ceremonial features but a routine part of life for Bronze Age communities, used repeatedly across generations.