It survives as a horseshoe-shaped mound of burnt material, roughly 10.5 metres long and half a metre high, its distinctive curved form the result of centuries of accumulated use rather than deliberate shaping.

Fulachtaí fia, the plural of fulacht fia, are generally understood to be Bronze Age cooking sites, typically consisting of a trough dug into the ground, a hearth for heating stones, and a mound of discarded, fire-cracked rock that built up over repeated use. The method involved heating stones in a fire and then dropping them into a water-filled trough to bring the water to a boil, a process that gradually shattered the stones and created the characteristic burnt mounds that archaeologists still find today. The Caherbarnagh example is not alone in its immediate landscape: a second fulacht fia lies approximately 25 metres to the north-east, suggesting this stretch of ground saw repeated or sustained activity during prehistory. Such clustering is not unusual; suitable water sources and terrain often drew repeated use to the same areas over generations.