These are the low, horseshoe-shaped mounds, typically Bronze Age in date, that mark the sites of ancient burnt-mound cooking places. The standard interpretation holds that stones were heated in a fire, then dropped into a water-filled trough to bring it to the boil, a process repeated until the cracked and shattered stones accumulated into the distinctive mound shape we see today. Kerry has an unusually high concentration of them, scattered across boggy ground and river margins, quietly accumulating for three or four thousand years before anyone thought to record them.

The fulacht fia at Fieries fits into a wider pattern of Bronze Age activity across the region, though the specific details of this particular site remain largely undocumented in any publicly available form. What is known is that fulachtaí fia, the plural form of the name, are almost always found near a reliable water source and tend to cluster in low-lying, sometimes waterlogged ground. The burnt mounds themselves are the main surviving evidence; the wooden troughs, if they existed, rarely survive except in exceptional anaerobic conditions. Theories about their function have ranged from cooking to brewing to communal bathing, with recent experimental archaeology lending some credibility to all three possibilities. The Fieries example, like many in Kerry, likely dates to somewhere within the broad span of the second millennium BC, though without excavation it is impossible to be more precise.