A fulacht fia, the term used for a type of prehistoric cooking or processing site typically identified by a horseshoe-shaped mound of fire-cracked stone and charcoal, once rose visibly enough from this landscape to be mapped. By 1943, when the Ordnance Survey recorded it on their six-inch series, it appeared as a mound. Today there is no visible surface trace at all.

Fulachta fiadh are among the most commonly encountered prehistoric monuments in Ireland, found in their thousands, usually in low-lying or marshy ground near water. The working principle involved heating stones in a fire, then dropping them into a water-filled trough to bring the water to a boil, leaving the cracked and spent stones to accumulate in a characteristic spread around the trough. What makes the Knockaneroe example quietly interesting is less what it is than what accompanies it: a second fulacht fia lies immediately adjacent, the pair sitting close enough together to suggest either prolonged use of a favoured spot or some form of concurrent activity. The land has since been improved for agriculture, a process of drainage and levelling that is responsible for the disappearance of the mound that was still legible in the mid-twentieth century.