The name translates roughly as "cooking place of the deer" or "cooking place of the wild," though what exactly went on at these sites has been debated for decades. The prevailing interpretation is that they served as outdoor cooking facilities, most likely during the Bronze Age, where stones were heated in a fire, dropped into a water-filled trough to bring it to the boil, and used to cook meat. The characteristic mound itself is the accumulated debris of cracked and fire-shattered stone, piled up over repeated use.

Fulachtaí fia are found across Ireland in enormous numbers, with Mayo having a considerable share. They tend to appear near streams or marshy ground, which makes practical sense given the need for a reliable water source. Most date to the Bronze Age, roughly 1500 to 500 BC, though some have produced dates extending into the Iron Age. The Fisherhill example is one of many such sites recorded across the county, each one a small, durable trace of people going about the routines of daily life in a landscape that would have looked quite different from the one we see today. Beyond the cooking hypothesis, some researchers have proposed alternative uses including sweat lodges, textile dyeing, or hide preparation, and the debate has not been fully settled.