This one is notable, in a quiet way, for what cannot be found. On the western shore of a small lake near Muckinish in County Clare, a fulacht fia, one of the horseshoe-shaped mounds of burnt and shattered stone left behind by prehistoric cooking or industrial activity, was recorded on a map but has resisted every subsequent attempt at physical confirmation. When fieldworkers visited in 1997, they found not an ancient mound but nearly two metres of reeds and bulrushes choking the lakeside, obscuring whatever lies beneath. The site was not located. It remains, officially, present on paper and absent on the ground.

The record traces back to Tim Robinson's 1977 map, which marks the feature touching the western shore of what he calls Ballinafad Lake. Robinson's cartographic work in the west of Ireland is regarded as unusually precise in its recording of minor antiquities and placename detail, so the inclusion carries some weight. What makes the Muckinish situation stranger still is that this is not an isolated anomaly. Two further fulachtaí fiadh were reported in the immediate vicinity, one roughly 100 metres to the north-east and another approximately 100 metres to the south-west, neither of them located either. Fulachtaí fiadh tend to cluster near water, since the process they represent involved heating stones in a fire and dropping them into a water-filled trough to bring it to a boil, so the lakeside setting is entirely consistent with the type. Three such sites in close proximity would suggest a patch of ground with repeated, possibly seasonal, prehistoric use. Whether that pattern genuinely exists beneath the reeds, or whether some of the reports reflect errors or duplications in the record, remains an open question.