It is gone now, destroyed in 1895 by turf cutting, and nothing remains at the surface to indicate it ever existed. What makes this place worth pausing over is not what survives but what was recorded before it vanished, and the quiet uncertainty that still surrounds its original purpose.

The passage was noted in 1937 by a researcher named Broker, who described it as roughly three feet square in cross-section, its sides boarded all round with planks of black bog oak, each board three inches by six inches and six feet in length. It lay within a ringfort, one of the thousands of roughly circular enclosed farmsteads built across Ireland during the early medieval period, typically between the sixth and tenth centuries. Structures of this kind, running underground from inside a ringfort's enclosure, are usually identified as souterrains, which were stone-lined or timber-lined tunnels used for storage, refuge, or ventilation. The bog oak lining at Liscreagh would have been unusual even by those standards. But the identification is not settled. When McCarthy revisited the site in 1977, he included it in a catalogue of souterrains while also raising the possibility that the original account might describe something else entirely, perhaps a water mill or a fulacht fia. A fulacht fia is a prehistoric cooking site, typically identified by a horseshoe-shaped mound of fire-cracked stone near a trough, and the association with timber and water would not be entirely out of place. The ambiguity has never been resolved, and the destruction of the feature before any systematic excavation means it is unlikely ever to be.