The term refers to mounds of burnt and fire-cracked stone, the accumulated debris of repeated heating, almost certainly used to boil water in a nearby trough or pit. At Lounaghan in County Kerry, one such mound sits on the southern bank of a small tributary of the Glashievhee stream, in rough pasture that still holds traces of an ancient, pre-bog field system around it. The mound itself is D-shaped, with a straight northern edge, measuring eight metres east to west and six metres north to south, and rising to about 0.8 metres. On its western side, the characteristic fill of heat-shattered stones and charcoal-enriched soil is visible at the surface.

What gives this particular site an added layer of interest is its company. A second possible fulacht fia lies on the northern bank of the same stream, suggesting that this stretch of water was a focus of activity over some period of time; running water was essential to the whole operation, used to replenish the cooking or heating trough. Thirty-five metres to the south stands a standing stone, a megalithic upright whose precise relationship to the burnt mounds is unknown but whose proximity is unlikely to be accidental. The pre-bog field boundaries enclosing the area point to a landscape that was once cleared, worked, and organised, long before the bog crept in and the modern pasture took its place. Together, these features suggest a small but purposeful prehistoric settlement zone rather than a single isolated monument.