What has been uncovered amounts to little more than a glimpse, roughly 1.2 metres of walling, but it is enough to identify the structure as a souterrain, one of those dry-stone underground chambers and passages built throughout early medieval Ireland, most commonly associated with ringfort settlements. Their precise function is still debated among archaeologists, with theories ranging from cold storage to refuge in times of danger, and quite possibly both at different moments.

The site was recorded in 1993, communicated by archaeologist Rose M. Cleary, and the details are spare but telling. The exposed section showed walls approximately 0.6 metres high, constructed without mortar in the drystone tradition, and capped with large flat roof lintels of the kind typical of souterrain construction across Munster. The relatively modest height of the surviving walls and the brevity of the exposed stretch suggest that much of the original structure remains underground, its full extent unknown. Courtmacsherry sits in a well-settled part of west Cork, and souterrains in the region are not uncommon, though most remain unexcavated, their relationship to any associated surface settlement unresolved.