This example, sitting in the townland of Derrynafeana on the Iveragh Peninsula in County Kerry, is a semicircular mound of fire-shattered stone roughly a metre high, measuring 9.2 metres north to south and 7 metres east to west, with a flat subcircular hollow at its centre approximately 2.6 by 2.5 metres across. That hollow is the key to understanding what the structure once was.

A fulacht fia, sometimes spelled fulacht fiadh, is the accumulated debris of a cooking or heating process that was repeated over many years, possibly centuries. The typical method involved heating stones in a fire, then dropping them into a water-filled trough to bring the water rapidly to the boil. The stones, repeatedly heated and cooled, eventually shattered and became unusable, and were discarded into a crescent-shaped mound around the trough. The result is precisely the kind of monument visible at Derrynafeana: a horseshoe of broken, heat-cracked stone framing a central depression where the trough once sat. Most fulachta fia in Ireland date to the Bronze Age, roughly 1500 to 500 BC, though the precise function of any individual site, whether for cooking meat, brewing, bathing, or industrial processes such as working leather, remains a matter of debate among archaeologists. The Iveragh Peninsula has a particularly dense concentration of such monuments, documented in the 1996 archaeological survey of South Kerry compiled by A. O'Sullivan and J. Sheehan.