That mound is now gone, levelled around 1980 according to local memory, though the scorched spread of material it left behind still covers roughly 22 metres by 18 metres in the grass.

What stood here was a fulacht fia, a type of Bronze Age cooking site found in remarkable numbers across Ireland, particularly in low-lying, waterlogged ground near streams and rivers. The typical form involves a trough dug into the earth, a hearth for heating stones, and a mound of the shattered, fire-cracked stones that accumulated as they were discarded after use. The process, as archaeologists understand it, involved heating the stones in a fire and dropping them into a water-filled trough to bring it to the boil, a technique that would have been efficient and repeatable. The location at Knockboy follows the pattern closely: proximity to a water source, open ground, and the characteristic dark stain of burnt and fragmented material that prehistoric cooking sites leave in the soil. Thousands of these sites are recorded across Ireland, making the fulacht fia one of the most common monuments in the Irish landscape, yet individual examples attract little ceremony.