What survives is a cropmark, the ghostly outline of a fosse, or circular ditch, that shows up in aerial and satellite photography as a faint ring roughly five metres in diameter. The fosse itself is long since filled in, but the soil above it retains enough difference in moisture and composition that the crops growing over it still betray its presence, colouring and ripening slightly differently from the surrounding field. It is the kind of feature that is entirely invisible to someone standing in the field and only legible from the air.

The ring was first identified from an aerial photograph taken on 13 July 1989, and later confirmed through satellite imagery captured in August 2015. A ring-ditch of this type is generally understood to be the remains of a prehistoric funerary or ritual monument, often the enclosing ditch that once surrounded a burial mound, the mound itself having been ploughed flat over the centuries. What makes the Cotterellsrath example particularly interesting is that it does not sit in isolation. A larger ring-ditch lies roughly 120 metres to the north, and a second lies about 50 metres to the north-northeast. The clustering of such features in a relatively small area suggests this patch of Kilkenny farmland may once have formed part of a wider ceremonial or burial landscape, a concentration that is easy to miss when all that remains are faint signatures in the soil, readable only when the light and the season are right.