In the case of a vanished ringfort in the low-lying undulating grassland of Kilgarriff, Co. Galway, the answer is largely a local nickname and a question mark. The site was known to people in the area as the "lair of a fox", a phrase that researchers took as a possible folk memory of something built underground rather than above it. A souterrain is a stone-lined underground passage or chamber, typically associated with early medieval ringforts in Ireland, and thought to have served for storage, refuge, or ventilation. The possibility that one existed here was never confirmed, because by the time anyone thought to look properly, the monument was already gone.

When a researcher visited in 1954, the ringfort was described as a stone-built enclosure with a single rampart, oval in plan, roughly 36.5 metres east to west, with no visible fosse (the ditch that typically surrounds such earthworks) and already much ruined and heavily overgrown. A scholar named Duignan, working from the same period, noted the fox-lair tradition and raised the possibility of a souterrain beneath the surface. The association is not far-fetched; souterrains frequently open from within the interior of ringforts, and their low, tunnel-like entrances could plausibly lodge in local memory as animal burrows or dens. But the monument was bulldozed sometime in the 1950s, leaving no visible surface trace. The grassland closed over it, and whatever lay beneath, confirmed or otherwise, was lost.