At Ballynacarriga in County Cork, the groundwork for the N25 Youghal Bypass in 2001 exposed an early medieval enclosure that had lain undisturbed on a south-facing slope above a stream valley for well over a thousand years. What made the discovery particularly striking was not just the enclosure itself but its relationship to a near-identical one immediately to its south, the two sitting side by side like paired rooms, divided and yet connected by a shared boundary ditch.

The enclosure measures roughly 51 metres east to west and 47 metres north to south, its northern and eastern sides defined by a U-shaped fosse, a defensive or boundary ditch, approximately 3.3 metres wide and around 3 metres deep. The southern boundary is formed by the northern fosse of the adjoining enclosure, suggesting the two were conceived as a single, expanding settlement rather than as separate and unrelated sites. Excavation revealed that all the activity was concentrated in the eastern half of the interior, where archaeologists uncovered the remains of three circular structures, three corn-drying kilns, and a possible souterrain, an underground stone-lined passage typically used for storage or as a place of refuge. Corn-drying kilns of this type were a common feature of early Irish farming settlements, used to dry grain before milling or storage, and their presence here in number points to a community engaged in sustained agricultural work. A radiocarbon date obtained from the lowest fill of the fosse placed the enclosure's construction in the period between roughly AD 620 and 700, and the excavator interpreted it as a seventh-century expansion of the older enclosure to the south.