Sometimes the most revealing thing about a place is its absence. On the Curragh, that broad expanse of open limestone grassland in Co. Kildare long associated with grazing rights, military training, and prehistoric activity, there once existed a circular enclosure roughly 45 metres across. It was recorded on the first edition of the Ordnance Survey six-inch map in 1838, drawn with enough confidence to suggest it was still legible in the landscape at that point. By the time the revised edition appeared in 1941, it was gone, at least from the cartographic record. No visible surface traces survive today.

The enclosure's shape and dimensions place it in the company of two ringbarrows that still exist nearby on the Curragh. A ringbarrow is a low circular earthwork, typically of prehistoric date, consisting of a central mound or flat area enclosed by a bank and ditch, and associated in Ireland with burial or ceremonial use. Whether this vanished example served a similar function is unknown, but its proximity to the surviving pair suggests it belonged to the same prehistoric landscape, a cluster of monuments that once marked this part of the plain in ways we can now only partially reconstruct. What erased it between the two surveys is not recorded. The Curragh has seen centuries of intensive use, and the gradual levelling of earthworks by grazing, military activity, or simple erosion is not unusual on such heavily trafficked ground.