These low, horseshoe-shaped mounds, typically found near water, are the burnt and discarded residue of ancient cooking sites, where stones were repeatedly heated in fire and plunged into water-filled troughs to bring them to the boil. The process left behind cracked and shattered rock, piled over centuries into the distinctive mounds that survive today. One such site lies at Toonagh in County Clare, quiet and unassuming in the landscape.

Fulachtaí fia date predominantly to the Bronze Age, roughly 1500 to 500 BC, though some have returned earlier or later dates. The name itself is a mediaeval Irish term sometimes translated loosely as "cooking place of the deer," though their exact function has been the subject of considerable debate. Brewing, textile dyeing, and communal bathing have all been proposed alongside the more straightforward cooking interpretation. What is consistent across the type is the setting: low-lying, wet ground, usually beside a stream or marsh, where a timber-lined trough could be filled naturally or with carried water. The Clare landscape, with its mix of river valleys and boggy hollows, is well suited to such sites, and the county holds a substantial number of recorded examples. The Toonagh site takes its place in that longer pattern, a fragment of everyday Bronze Age life preserved beneath the soil.