In a field near Prumpelstown in County Kildare, something circular lies just beneath the surface, invisible at ground level but legible from the air. Aerial photographs reveal a cropmark, a ghostly ring formed where ancient disturbed soil causes crops above to grow differently from their surroundings, tracing the outline of a fosse, a defensive or enclosing ditch, that defines a small circular area no more than about fifteen metres across.

The feature is tentatively identified as a ringbarrow or ringditch, two closely related monument types associated with prehistoric funerary or ceremonial practice. A ringbarrow typically consists of a low central mound enclosed by a circular ditch and sometimes an outer bank, while a ringditch is the cropmark trace left by that enclosing ditch alone, the mound itself long since ploughed flat. At fifteen metres in diameter, this is a modest example, the kind of quiet burial marker that once dotted the Irish landscape in considerable numbers and that centuries of agriculture have reduced, in many cases, to nothing more than a faint signal in a summer wheat field photographed from a light aircraft.