The example at Cunnagher in County Mayo is one such site, a low mound of burnt and fire-cracked stone that, to an untrained eye, looks like little more than a grassy hump in a field. A fulacht fia, the term used for these Bronze Age cooking or processing sites, typically consists of a horseshoe-shaped mound of shattered stone surrounding a trough dug into the ground. The accepted understanding is that stones were heated in a fire and then dropped into the water-filled trough, bringing it rapidly to the boil. Whether the purpose was cooking meat, preparing hides, or something else entirely remains a matter of debate among archaeologists.

The site at Cunnagher belongs to a category of monument that was largely invisible to scholarly attention until the twentieth century, when systematic field survey began to reveal just how densely these features are distributed across the Irish countryside, particularly in low-lying, waterlogged areas where the timber and stone components survived beneath layers of peat. Mayo, with its boggy terrain and extensive upland margins, is well-suited to their preservation. The burnt mounds that form them are composed almost entirely of heat-shattered sandstone or other local rock, the accumulated debris of repeated firings over what may have been centuries of intermittent use. Individual sites range from modest spreads a few metres across to substantial mounds several metres in height.