The one at Cloghadockan in County Mayo is typical in the best sense: a low, horseshoe-shaped mound of fire-cracked stone sitting quietly in the landscape, easy to overlook, difficult to explain entirely. The name translates roughly as "wild deer cooking place," though the cooking hypothesis, while widely accepted, has never fully settled the debate about what these sites were actually for.

Fulachtaí fia were in use primarily during the Bronze Age, roughly 1500 to 500 BC, and the basic technology involved was straightforward. A trough, usually timber-lined or cut into the ground, was filled with water. Stones were heated in a nearby fire and dropped into the trough until the water boiled, at which point meat could be cooked, hides tanned, or, as some researchers have proposed, the hot water used for bathing. The spent, shattered stones were raked to the side after each use, and over time those discarded heaps built up into the distinctive crescent mounds that survive today. Experiments have shown the method works efficiently, bringing a large volume of water to a boil within a reasonable time. What drove the continued use of this apparently labour-intensive process, when pottery and other cooking technologies existed alongside it, remains an open question. The Cloghadockan example sits within a county that has a dense concentration of prehistoric remains, a reflection of Mayo's extensive boglands, which have preserved early features that elsewhere were lost to agriculture and development.