That is, in a sense, precisely what makes it interesting. On a gently south-facing slope in County Cork, above a sharp drop to a stream bed, a ringfort once stood that has been so thoroughly erased from the landscape that it leaves no visible surface trace whatsoever. The only way to see its outline at all is from the air, where a cropmark, the faint differential in plant growth that betrays buried earthworks beneath a field, reveals the ghost of a circular enclosure complete with bank and external fosse, its northern arc cut through by a later field boundary.

Ringforts, sometimes called raths, were the most common settlement type in early medieval Ireland, typically consisting of a raised circular bank enclosing a farmstead. They number in the tens of thousands across the country. The one at Boherascrub was levelled sometime in the early 1970s, a fate that befell many such sites during a period of agricultural intensification. What makes this particular loss notable is the discovery, recorded by Cleary in 1987, that when the souterrain in the interior came to light, traces of the ringfort were still just about legible on the ground. A souterrain is an underground stone-built passage or chamber, typically associated with early medieval settlement, used for storage and possibly as a place of refuge. Its presence here confirms that whatever stood at Boherascrub was a functioning early medieval enclosure, not merely a field boundary or later earthwork. By the time the connection was made between the vanished fort and its underground structure, the surface evidence had already gone.