In a field in Prumpelstown, County Kildare, there is something that cannot be seen from the ground at all. No earthwork survives, no visible bank or ditch, no stone to stub a toe on. What exists instead is a ghostly circular mark that appears only in aerial photographs, when dry summers cause the grass or grain above buried features to grow differently from the surrounding crop. These marks, known as cropmarks, reveal the outlines of features long since levelled, and in this case they trace a ring-ditch, a roughly circular trench that was once dug into the earth.

Ring-ditches are generally understood to be the remains of prehistoric funerary or ceremonial monuments, often all that survives of a round barrow after centuries of ploughing have removed the central mound. The Prumpelstown example was first identified in August 1995, when Dr. Gillian Barrett captured it during an aerial photographic survey. The resulting photograph, recorded as GB95.FU.30, shows the cropmark clearly enough to plot. What makes this site a little more interesting than a lone anomaly is that a second ring-ditch lies in close proximity, the two together suggesting this corner of Kildare may once have held some significance as a place of burial or ritual in the prehistoric landscape.