The structure is a souterrain, a type of man-made underground chamber associated with early medieval settlement in Ireland, typically used for storage, refuge, or both. What makes this particular example quietly extraordinary is not its archaeology alone but the record left by someone who was there when it could still be entered.

In 1858 or 1859, a writer named Keatinge visited the site and recorded what he found with unusual care. On the eastern side of a ringfort, the circular earthwork enclosure to which the souterrain belongs, he discovered the remains of a small drystone structure built at the entrance, describing its beehive or bell-shaped form as showing "great tact and ingenuity" despite being made of the roughest stones. Below this, a passage choked with debris led inward. Keatinge noted that local people had already ventured a short way in, and he described how one man, going further with a light, found the tunnel widening enough that he could stand upright. Beyond that point, this man reported rooms of some extent, with several smaller chambers branching off to the sides. It is a vivid account of a functioning underground space, the kind of detail that tends to disappear once a site silts up or collapses entirely. By the time the first Ordnance Survey mapped the area in 1840, the souterrain went unrecorded, and the revised edition of 1904 noted nothing either, suggesting it was already little known or already buried.

Today there is no visible surface trace of the souterrain. The ringfort it belongs to still exists as a separate recorded feature, but the underground passages described by Keatinge have left nothing for a visitor to see. What remains is the account itself, a mid-nineteenth century glimpse of a hollow, roomy interior that has since closed itself off entirely.