In a field near Prumpelstown in County Kildare, something circular lies just beneath the soil, invisible to anyone walking past but legible from the air as a faint ring pressed into the earth. Aerial photography has revealed a cropmark tracing a fosse, essentially a shallow ditch or depression, that curves around a small enclosed area no more than fifteen metres across at its widest point.

Cropmarks form when buried features affect how crops grow above them; a filled-in ditch retains more moisture, producing taller or greener growth that shows up clearly in aerial photographs taken during dry spells. In this case, the circular outline suggests either a ringbarrow or a ringditch, two related prehistoric monument types. A ringbarrow is typically a low burial mound enclosed by a surrounding ditch, while a ringditch may be all that survives of a barrow once the central mound has been ploughed flat over centuries of agriculture. Either way, the feature at Prumpelstown belongs to a class of monument most commonly associated with Bronze Age funerary traditions, when the dead were sometimes interred beneath earthen mounds and enclosed within a defined ritual boundary. At roughly fifteen metres in diameter, this is a modest example, and its survival as a cropmark alone suggests that any upstanding earthwork has long since been levelled by cultivation.