They appear as low, horseshoe-shaped mounds, typically brownish and waterlogged, and for a long time nobody was entirely sure what Bronze Age communities were actually doing at them. The leading theory involves cooking: stones would be heated in a fire, dropped into a trough of water to bring it rapidly to the boil, and used to prepare meat. Other proposals include brewing, hide-working, or bathing. The mound itself is the byproduct, built up over time from the cracked and discarded fire-shattered stones. One such site sits at Ballinrea in County Cork, a quiet addition to the dense archaeological record of a county that has more of these features than almost anywhere else in Ireland.

Cork's concentration of fulachtaí fia has long drawn archaeological attention, with the low-lying, wet ground conditions of the county being particularly suited both to their original use and to their survival in the landscape. Bronze Age in date, broadly speaking from around 1500 BC onwards, these sites were in use over a very long period and are rarely dramatic in appearance. They are easy to miss, easy to overlook, and frequently discovered only during development surveys or field walking. The example at Ballinrea is recorded as part of that wider county picture, though detailed documentation specific to this site remains limited in what is publicly available at present.