The one recorded at Ballinrea, in County Cork, is typical in its anonymity, a low horseshoe-shaped mound of fire-cracked stone that might easily be mistaken for a natural rise in the ground. The name, roughly translating from Irish as "cooking place of the deer" or possibly "cooking place of the wild," points to their most widely accepted interpretation: outdoor cooking sites, probably Bronze Age in date, where stones were heated in a fire and dropped into a water-filled trough to bring it to the boil. The cracked and spent stones were then piled to the side, building up over repeated use into the characteristic mound that survives today.

Fulachtaí fia tend to cluster near water sources, and Cork is particularly rich in them, the county's boggy lowlands and river margins offering ideal conditions both for their original use and for their subsequent preservation beneath accumulating peat. The Bronze Age date assigned to most examples, broadly spanning from around 2000 BC to 500 BC, makes them roughly contemporary with the megalithic tombs and stone circles that punctuate the same landscape. Some researchers have proposed alternative functions beyond cooking, including sweat houses, dyeing vats, or brewing vessels, and experimental archaeology has shown that all of these are technically feasible using the hot-stone method. No single explanation has yet settled the debate.

The Ballinrea example sits within a landscape that has been farmed and modified over millennia, and such monuments are often easier to recognise in low winter light or after rain, when the slight elevation of the mound becomes more legible against the surrounding ground.