The term, which loosely translates from Old Irish as something like "cooking place of the deer" or "cooking place of the wild," refers to the horseshoe-shaped mounds of burnt and shattered stone that accumulate beside ancient hearths and water sources. The basic principle involves heating stones in a fire and dropping them into a water-filled trough until the water boils, a method that works surprisingly well and leaves behind a distinctive signature in the soil. The example recorded near An Cheapaigh in County Kerry is one such site, its presence in this corner of the southwest a quiet reminder that the land here has been worked and lived in for a very long time.

Most fulachta fia in Ireland date to the Bronze Age, broadly speaking the period from around 2500 to 500 BC, though some have produced dates from the Iron Age and even later periods. They tend to cluster near wetlands, streams, or springs, since a reliable water source was essential to their function. The burnt stone mounds that survive above ground are essentially the debris of repeated use, cracked and discarded rock that could no longer hold heat efficiently piling up at the edge of the working area. What they were used for remains genuinely open to debate. Cooking is the traditional explanation, and experimental archaeology has confirmed it is entirely workable, but some researchers have proposed uses ranging from textile processing to bathing to brewing. No single explanation has closed the argument, which is part of what makes these modest, mossy mounds so persistently interesting.