Somewhere beneath the fields of Prumpelstown in County Kildare, something circular lies buried, invisible to anyone standing on the ground but legible from the air as a faint discolouration in the crops above it. This is how many of Ireland's ancient enclosures are first encountered, not by excavation or accident, but by the particular alchemy of dry summers and low-flying aircraft.

The site was first recorded in August 1995, when aerial archaeologist Dr. Gillian Barrett photographed a cropmark over the area. Cropmarks form when buried features, walls, ditches, pits, compress or enrich the soil above them in ways that affect how crops grow, producing subtle differences in height and colour that become readable from altitude, especially during dry spells when the contrast sharpens. The photograph, catalogued as GB95.FU.22, shows the outline of an enclosure, a broad category that could encompass anything from a prehistoric farmstead to an early medieval ringfort, the circular banked settlements that once numbered in the tens of thousands across Ireland. Without excavation, the precise date and function of what lies beneath Prumpelstown's fields remains open.