It measures roughly seven metres long, six and a half metres wide, and less than a metre high, yet it represents one of the most widespread and still only partially understood monument types in the Irish landscape. This is a fulacht fia, a term used for the distinctive crescent or horseshoe-shaped mounds of fire-cracked stone that survive in their thousands across the country, most of them in low-lying or waterlogged ground.

A fulacht fia is generally understood to have functioned as a cooking site, most likely in use during the Bronze Age. The typical method involved heating stones in a fire and dropping them into a water-filled trough until the water boiled, leaving behind the shattered, heat-stressed fragments that gradually accumulated into the mound visible today. The boggy setting at Lismeelcunnin is entirely characteristic; water access was essential, and the waterlogged ground has helped preserve the mound's profile over millennia. This particular example was recorded by Bowman in 1934, noted in a publication that year alongside a second fulacht fia on the same landholding, then belonging to a D. Donovan. The two sites sit close enough together to suggest this stretch of ground saw repeated or prolonged use, though whether that was seasonal, ceremonial, or simply practical remains open to interpretation.