The one at Carrigagrenane in County Cork sits in pasture on a break in a south-facing slope, its presence announced only by a slightly raised circular area roughly twenty-two metres across from north to south. What makes it worth pausing over is a detail in its construction: the earthen bank enclosing it from the west round to the south-west has been stone-faced on the inside, a refinement that would have given the inner wall a neater, more deliberate finish than simple piled earth alone.

Ringforts, sometimes called raths when they are earthen rather than stone, were the standard settlement form in early medieval Ireland, typically dating from somewhere between the fifth and twelfth centuries. They functioned primarily as enclosed farmsteads, the bank and any associated ditch keeping livestock in and opportunistic raiders or wandering animals out, while a family and their dependants lived and worked within the enclosure. The stone-facing noted here on the interior of the bank suggests a degree of additional effort, possibly reflecting the status or resources of whoever built it, or simply the practical availability of stone on this particular stretch of Cork hillside. The site retains its bank to a height of around 1.3 metres, which is a reasonable survival for a structure that has been embedded in agricultural land for over a millennium.