The one at Derryduff, in West Cork, offers something rather more stripped back: a single arc of earthen bank, curving perhaps eight metres from east to south-east, rising to about one and a half metres in height, and sitting atop a low hillock in open pasture. It is, in other words, a fragment, though a fragment substantial enough to have been formally recorded.

Ringforts, sometimes called raths, were the most common form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the twelfth century. They were enclosed farmsteads rather than fortifications in any military sense, the surrounding bank and ditch serving to define a household's space and protect livestock. Thousands survive across the country in varying states of preservation. At Derryduff, only the eastern arc of what would once have been a circular or near-circular enclosure remains, but that surviving curve is enough to fix the site's character and age within a recognisable tradition. The hillock setting is typical too; slightly elevated ground gave a degree of natural drainage and visibility over the surrounding area, practical advantages for any farming family in early Christian Ireland.