Somewhere beneath the farmland at Tullygorey in County Kildare, the outline of an ancient enclosure persists, invisible at ground level but legible from the air as a ghostly rectangle pressed into the soil. It belongs to a category of site that reveals itself only under particular conditions, when growing crops betray the buried features beneath them through subtle differences in colour and height.

The site came to light on 13 July 1990, when Dr. Gillian Barrett spotted it during an aerial photographic survey. The resulting photograph, catalogued as GB90.BT.07, captured a cropmark, a pattern formed when crops growing over a buried fosse, or ditch, respond differently to the soil conditions created by that feature. A fosse of this kind typically marks the perimeter of an enclosure, a defined area that might once have served a domestic, agricultural, or ceremonial purpose. The rectangular form is notable; many Irish enclosures are roughly circular, so a rectangular outline can suggest different origins or functions, though without excavation the date and purpose of this particular example remain open questions.