Cultivation ridges across the surface stop noticeably short of a roughly circular area about ten metres in diameter, leaving it untouched. Whether this was deliberate caution or simply practical instinct is unclear, but underneath that patch of ground sits an Early Medieval underground structure whose roofing slabs lie close enough to the surface to have made ploughing through it a risky proposition.

The feature is a souterrain, an underground passage and chamber system built without mortar using carefully laid drystone walling. Souterrains are found across Ireland and are generally associated with Early Medieval ringforts, used variously for storage, refuge, or both. Here, it forms part of a circular univallate rath, a single-ditched ringfort, positioned on the eastern side of the valley. Excavation of the south-easterly sector uncovered a NE-SW running passage, less than a metre wide and barely tall enough to crouch in, which connects via a low creepway to an approximately square chamber roughly two metres across. The creepway itself is a remarkably tight squeeze: just 0.34 metres wide and no higher than 0.34 metres at its maximum. A further opening in the north-west wall of the chamber suggests at least one additional passage or chamber beyond, though this portion remains inaccessible. The walls incline slightly inward beneath a lintelled roof, a construction technique that distributes the weight of the stone above without mortar to hold it. The description of this site was first published by J. Cuppage in the 1986 Dingle Peninsula archaeological survey, a systematic catalogue of the extraordinary concentration of ancient monuments on the Corca Dhuibhne peninsula.