In a field near Levitstown in County Kildare, a circle lies buried in the earth, invisible to anyone walking the ground but legible from the air as a faint chromatic signature in the growing crops above it. This is a ring-ditch, the circular trench that once surrounded a prehistoric burial mound or funerary enclosure, and though the mound itself has long since been ploughed away, the ditch beneath the surface holds enough moisture and organic material to make the grass or grain above it grow at a slightly different rate, leaving a shadow that only becomes apparent from altitude, and only in the right season.

The site came to light in 1991, when Dr. Gillian Barrett spotted the cropmark during an aerial photographic survey. The photograph, catalogued as GB91.DV.38, captured that fleeting moment when the geometry of an ancient feature briefly reasserts itself through the skin of a modern agricultural field. Ring-ditches of this kind are scattered across the Irish midlands and east, often the only surface trace of Bronze Age or earlier burial activity, and many have been identified through exactly this method, patient observation from light aircraft during dry summers when soil differences are most pronounced.