Its entrance was blocked in the early 1960s, and it has quietly disappeared from accessible knowledge ever since, known now only through local memory and the descriptions that memory preserved.

The structure is a souterrain, a type of underground chamber or tunnel built from drystone construction, meaning stones laid without mortar, fitted tightly together by skill rather than binding material. Souterrains appear across Ireland from the early medieval period onward, and were used variously for storage, shelter, or refuge, though their precise function often varied by site and period. This one on Knocknaskereighta is recorded as being of drystone construction, which places it within that long tradition, though without excavation little more can be said with confidence. The surrounding area of the Iveragh Peninsula in south Kerry is particularly rich in early medieval archaeology, and a souterrain tucked into a mountain slope overlooking the bay would not be out of place in that broader landscape of hidden and half-forgotten remains.

Because the entrance was sealed decades ago and the site is not marked on standard maps, there is no practical way to visit or inspect it. What lingers is the outline of a place that exists in the record largely because local people remembered it was there, holding onto the knowledge of something underground and old on a hillside that most maps insist is simply empty ground.