A souterrain, the term for an artificial underground passage or chamber typically associated with early medieval Irish settlement, was recorded here in careful detail in the late nineteenth century. What makes it quietly compelling is not just its existence, but the complexity it hints at: two connected chambers, a sloping entrance passage, and a further collapsed passage suggesting that what survives may only be part of something larger.

The site was described by Gillman in 1896, who recorded a stone-built entrance passage approached by a short slope from the ringfort interior. The entrance itself measured just two feet by two feet, opening into a passage roughly seven feet long, covered by two stone slabs and descending to the south-east. From there, a low earth-cut creepway, the kind of tight connecting tunnel that requires hands and knees to navigate, led into the first chamber: approximately ten and a half feet long, four and a half feet wide, and just under four feet high, with its long axis running east to west. A second creepway connected this chamber to a second, similarly sized chamber oriented west-northwest to east-southeast. In the south-west corner of the first chamber, a collapsed passage hints at the possibility of further chambers beyond the known extent of the system. Writing in 1977, McCarthy noted that certain stone slabs at the corners of the chambers may have served as facings to a construction pit, suggesting the chambers were dug from above before being roofed over, rather than tunnelled from within.

The entrance to the souterrain is now closed, meaning the underground chambers themselves are no longer accessible. The ringfort in which they sit remains the visible presence on the landscape, its earthen banks marking the boundary of what was once a defended farmstead, and the souterrain beneath it a reminder of how much early medieval life was organised around concealment, storage, and refuge.