The operative word is "reputed": the structure's existence rests on local knowledge rather than on excavation or verified survey, which places it in an intriguing category of sites that are neither confirmed nor dismissed, simply unresolved.

A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval settlement in Ireland, and generally thought to have served for storage, refuge, or both. They are found across the country, but the Iveragh Peninsula has a particularly dense archaeology, its landscape shaped by millennia of habitation that the area's relative remoteness has done much to preserve. The reference to this particular site comes from a 1996 archaeological survey of south Kerry compiled by A. O'Sullivan and J. Sheehan, which catalogued known and reputed monuments across the peninsula. That the compilers flagged it at all suggests the local tradition of its existence was considered worth recording, even without physical confirmation.