A midden is essentially a refuse heap, the kind of domestic deposit that archaeologists prize precisely because it preserves the unglamorous residue of everyday life. This particular one went unnoticed until construction workers broke ground for a new school building, at which point the past abruptly surfaced.

The pit measures roughly five metres north to south and just over two metres east to west, cut to a maximum depth of about sixty centimetres into the subsoil. When archaeologist M. J. O'Kelly excavated it in the mid-1950s, he found a carefully structured deposit rather than a simple heap. The base had been lined with small boulders and flat stones, and further layers of flagstones were laid among the shells, suggesting some deliberate organisation rather than casual dumping. Hearths were identified at different levels within the fill, which implies the site was used repeatedly over time rather than abandoned after a single episode. The bulk of the contents were oyster shells, supplemented by a small quantity of animal bones and fragments of glazed pottery. That pottery has been dated to the late thirteenth and early fourteenth centuries, placing the deposit in a period when the Anglo-Norman settlement of east Cork was well established and coastal communities along Cork Harbour were drawing on the estuary's shellfish in quantity. Beyond the pit itself, the surrounding subsoil showed further hollows and undulations also containing habitation refuse, hinting that the activity here extended over a wider area than the single excavated feature.