The catch is that nobody has seen it. No opening breaks the surface, no hollow ground betrays its presence, and yet the idea of it persists.

The case for its existence rests on two things: structural indications and local tradition, both cited by a Fahey writing in 1893. The site in question is a cashel, a type of early medieval ringfort built from dry-stone walling rather than earthen banks, and souterrains were commonly incorporated into such enclosures across Ireland. Fahey's language is cautious, describing a probable "cave" within the "fort", and that caution has proven warranted. No visible surface trace of the feature survives today, leaving the question open. It is the kind of site that exists almost entirely in the conditional tense, a thing that probably is there, that once was known about locally, and that has since been swallowed by time and ground.