The one at Kilmore in County Cork is a quiet example of a type that appears so frequently in fields, bogs, and river margins that farmers have long since learned to work around them without giving them much thought. A fulacht fia typically takes the form of a low, horseshoe-shaped or kidney-shaped mound of fire-cracked stone, dark and heat-shattered, built up over many uses beside a water source. The stones were heated in a fire and then dropped into a water-filled trough, probably timber-lined, bringing the water rapidly to a boil.

What the troughs were actually used for remains genuinely contested. The cooking hypothesis has dominated since the mid-twentieth century, when the archaeologist M. A. O'Kelly demonstrated at a reconstructed site that a fulacht could bring water to the boil in around eighteen minutes and sustain it long enough to cook a joint of meat. More recent experimental work has proposed alternatives, including brewing, hide-working, and bathing. Most of these sites date to the Bronze Age, roughly 1500 to 500 BC, though some have produced earlier or later dates. Their clustering near streams and marshy ground is consistent across the country, and Cork is one of the counties where they survive in particularly large numbers, preserved in part by the boggy conditions that discourage deep ploughing. The Kilmore example sits within this broader pattern, a remnant of repeated, routine activity carried out at the same spot over what was likely a long period of use.