The one at Ballybrowney in County Cork is more elaborately defended than most, with three concentric earthen banks separated by ditches, or fosses, arranged around a roughly circular area some 38 metres across. Three banks were a mark of considerable status in early medieval Ireland, and the multiple entrance gaps, several with surviving causeways bridging the ditches between them, suggest a site that was carefully managed and used over time. The outermost bank survives from the southern arc around to the north-west, where to the east it has been absorbed into a field boundary, one of the more common fates for earthworks that happened to lie conveniently along a farmer's property line.

What sets Ballybrowney apart from a straightforward defensive enclosure is what appears in the space between the inner and middle banks to the north-north-east. Two radial banks run across the gap there, combining with the existing ringfort banks to form a small rectangular structure measuring roughly 7.5 metres by 6.5 metres, with its own narrow entrance cut through the middle bank. The 1842 Ordnance Survey six-inch map, one of the earliest systematic surveys of the Irish countryside, marks this spot as the "site of" a Roman Catholic chapel. It is a common enough pattern in Ireland for post-medieval or early modern Catholic worship to have taken place within or alongside older earthworks, often because such locations were already understood as set apart from ordinary agricultural land. Whether the rectangular structure at Ballybrowney was built specifically as a chapel or adapted from earlier features is not clear, but the overlap of early medieval enclosure and later religious use makes this a quietly layered piece of landscape. The site sits on a gentle south-east-facing slope overlooking the Bride river, in what is now tillage ground.