It measures roughly 1.6 metres square and barely 20 centimetres high, which is to say it looks like almost nothing at all. But beneath it lies the blocked entrance to a souterrain, an underground structure of the kind built throughout early medieval Ireland, typically comprising dry-laid stone passages and chambers used for storage, refuge, or both.

The 1913 edition of the Ordnance Survey six-inch map marks the spot simply as "Cave", which suggests that by then the structure's true character was already half-forgotten, its entrance presumably still visible enough to warrant a note but its origins unclear to whoever supplied the name. Local tradition, passed down rather than excavated, holds that the souterrain is of drystone construction, meaning the walls were built without mortar, and that it extends into a series of interconnected chambers underground. The passage itself has not been formally explored or recorded from within, so what lies beneath remains a matter of inherited knowledge rather than documented fact.

The site sits in gently undulating pasture, and the blocked entrance gives no real impression of what may survive below. The rubble that seals it offers no invitation, and the passage is not accessible to visitors.