Then, in the 1950s, they were levelled during land reclamation works, and whatever record they held in the earth was largely lost. What remained were the memories of the landowner, who recalled that the mounds had been composed of stone, and a scattering of burnt stone across the field that offered a quiet but telling clue to their origin.

That clue points toward fulachta fiadh, a class of prehistoric cooking site found in great numbers across Ireland, particularly in low-lying, waterlogged ground near rivers or streams. The typical fulacht fia consists of a horseshoe-shaped mound of fire-cracked stone, built up over repeated use as stones were heated in a fire and then dropped into a water-filled trough to bring it to a boil, often for cooking meat. The mounds at Carhoobeg fit the profile well: their position in a marshy riverside field is precisely the kind of setting these sites favour, and the burnt stone scattered across the ground is the signature residue of the process. Most fulachta fiadh date to the Bronze Age, roughly 1500 to 500 BC, though the tradition may span a wider period. The four mounds here were never formally excavated before they disappeared, so the identification remains probable rather than certain.