No mound, no earthwork, no stone. And yet the ground almost certainly holds a fulacht fia, one of the thousands of prehistoric cooking sites scattered across the Irish landscape, typically identified by their horseshoe-shaped mounds of fire-cracked stone and charcoal-dark soil. The absence of any surface trace at Cleanrath is itself part of the story.

A fulacht fia, at its most basic, was a place for heating water. Stones were fired in a hearth, then dropped into a water-filled trough, usually timber-lined, until the water boiled. The cracked and spent stones were discarded into a mound nearby, and it is these distinctive dumps of shattered rock that survive across boggy and low-lying ground throughout Ireland, often close to streams or springs, as here at Cleanrath. The site was recorded on the Ordnance Survey six-inch map of 1937, but only as a "site of", meaning even then there was uncertainty about whether anything remained above ground. By the time the Archaeological Inventory of County Cork documented it, no visible surface trace could be found at all. The working explanation is that the spot has been covered by recently dumped clay, a mundane fate for something that may date back several thousand years to the Bronze Age, when fulachtaí fia were in widespread use across the country.