In 1988, ground levels at a stock yard in Barnagore, County Cork were being lowered ahead of surfacing, and the machinery doing the work broke through the ceiling of a stone-built underground chamber that had gone unnoticed for centuries. A souterrain is an artificial underground passage or chamber, typically constructed during the early medieval period in Ireland, often associated with a nearby settlement and thought to have served as a place of refuge, storage, or both.

Jerry O'Sullivan of University College Cork investigated what remained. The chamber measured two metres in length and 1.2 metres in width, with its long axis running east to west. At the eastern end, a creepway, the narrow connecting passage typical of multi-chambered souterrains, had been blocked off, suggesting that further chambers may lie beyond. A stone-built air vent survives on the southern side, a detail that points to some care in the original construction. By the time of investigation, only the lintels directly over the creepway were still in place; the rest had been displaced by the machinery, and the floor was covered with spoil from the disturbance. The blocked creepway leaves open the question of what, if anything, remains intact on the other side of it.