These low, horseshoe-shaped mounds, typically found near water, are the remains of ancient cooking sites, probably Bronze Age in date, where stones were heated in fire and then dropped into a water-filled trough to bring it to the boil. The process left behind cracked, fire-shattered stone that accumulated over repeated use into the distinctive mound shape still visible today. The example at Knockaunroe, in County Clare, is one such site, its presence in the landscape a small but legible trace of organised, repeated activity stretching back perhaps three or four thousand years.

Fulachtaí fia are found throughout Ireland, but Clare has a notable concentration of them, often turning up in low-lying, boggy ground where the water table would have made a natural trough easy to maintain. The name itself, loosely translated as "cooking place of the deer" or "wild place", appears in later medieval Irish texts, though whether it accurately describes Bronze Age practice or is a much later folk interpretation remains debated among archaeologists. Experimental archaeology has shown the method is genuinely effective for boiling large quantities of water quickly, and some researchers have proposed the sites served social or ritual functions beyond simple cooking, perhaps for bathing, brewing, or communal gathering.