The giveaway is the grass: a noticeably thicker growth of long grass and plantain traces a rough horseshoe shape across the rough pasture, marking the outline of a fulacht fia, one of the most common yet least understood monument types in the Irish landscape.

A fulacht fia is a Bronze Age cooking site, typically consisting of a horseshoe-shaped mound of fire-cracked stones beside a water source. The method was simple: stones were heated in a fire and dropped into a water-filled trough, bringing the water rapidly to the boil. Over time, the shattered, heat-spent stones were discarded to either side of the trough, building up the characteristic curved mound. At Clooneen, that mound measures roughly eleven metres across its longest axis and stands only about 0.3 metres high, low enough to be easily missed. The arms of the horseshoe enclose a central depression, open to the north-east, which is thought to mark the position of the original trough. Beneath the surface, black peaty soil overlies a concentration of stones, the same fire-cracked debris that gives these sites their distinctive character across Ireland. A pool recorded on a 1930 Ordnance Survey map, roughly thirty metres to the north-east, has since dried up; that pool would almost certainly have supplied the water the site required. Immediately to the south-west, the ground rises slightly and becomes drier, which is typical of the pattern: the hearth and working area tended to sit just above the waterlogged ground, close to the source but not submerged by it.