The one at Coolanagh in County Cork came to light not through deliberate excavation but through land reclamation work, the kind of agricultural improvement that has quietly erased or exposed countless such features across the Irish countryside. It was a drain, cut to manage the land, that broke into the structure and destroyed its north-eastern portion before anyone knew it was there.

What remained was recorded in two earth-cut chambers, modest in scale but intact enough to document. The first measured roughly 1.1 metres in length and 0.9 metres in width; the second was slightly larger, at 1.5 metres long and 1.0 metre wide. Access for recording was gained through the open side of the drain that had already compromised the structure. The details were communicated by R. M. Cleary, and the site was included in the Archaeological Inventory of County Cork, the published survey of West Cork's known monuments. The dimensions suggest a small, functional construction, the sort of souterrain that would have served a nearby settlement rather than formed part of any grander complex, though no associated surface features are recorded here.