That kind of ghostly outline, known as a cropmark, forms when buried ditches retain more moisture than the surrounding soil, causing the vegetation above them to grow fractionally taller and greener. An aerial photograph taken in July 1989 as part of the Cork Aerial Survey and Archaeology Programme captured exactly this, revealing the double-fossed outline of a circular enclosure roughly thirty metres in diameter, sitting on the eastern side of a field fence.

The site is likely the remains of a ringfort, the most common monument type in the Irish archaeological landscape. Ringforts were enclosed farmsteads, typically dating from the early medieval period, roughly 500 to 1000 AD, in which a family and their livestock lived within one or more earthen banks and ditches. The double-concentric arrangement here, two fosses rather than one, suggests either a site of some status or one that required additional defensive depth. What makes the Boherascrub enclosure quietly interesting is its context: a confirmed ringfort lies approximately two hundred metres to the north-east, and a probable second one sits around the same distance to the south-east. Small clusters like this are not uncommon in Cork, where early medieval farming communities sometimes settled in loose proximity, but seeing three such sites within a few hundred metres of one another gives a faint sense of a once-inhabited landscape that has otherwise entirely disappeared from view.