It came to light not through formal excavation but through local knowledge, passed on in the way that so much Irish archaeology survives, as a memory embedded in the community rather than a mark on any official map. That informal quality is part of what makes it interesting.

A souterrain is an underground passage or chamber, typically constructed during the early medieval period in Ireland, between roughly the sixth and twelfth centuries. They were built from stone, sometimes cut into bedrock, and are found in association with ringforts and farmsteads across the island. Their precise function is still debated, though cold storage, refuge, and ventilation for above-ground structures are the most commonly proposed uses. The Ballyglissane example sits in pasture land to the north-north-east of a second possible souterrain in the same townland, suggesting that this small area of east Cork may have once supported a cluster of early medieval activity, though the relationship between the two features remains uncertain. The detail that survives, a passage covered by slabs and running east to west, is thin but suggestive.