At Knockroe in County Clare, a circular enclosure roughly nineteen metres in diameter was recorded on the 1842 edition of the Ordnance Survey six-inch map, marked with hachures, the small radiating lines cartographers used to indicate an earthwork or raised feature. By May 1999, when someone went to look for it in person, it could not be located at all. The land had moved on without it.

The enclosure sat on low-lying boggy pasture, partly cleared and drained, with hillocks rising to the north and south. Circular enclosures of this kind are among the most common archaeological features in the Irish landscape; they range from prehistoric ringforts, which typically served as enclosed farmsteads, to later ecclesiastical enclosures, and their exact function is rarely obvious from surface remains alone. What makes the Knockroe example quietly interesting is the gap between its documentary afterlife and its physical disappearance. Aerial photography from the 2013 to 2018 Aerial Premium survey shows its outline still legible as a cropmark or soil mark, a ghost pressed into the field even after levelling. A field boundary running roughly north-northwest to south-southeast cuts across it, suggesting the enclosure had already been absorbed into the working agricultural landscape before that later division was imposed.