Not ruined, not overgrown, simply gone, leaving no earthwork, no bank, no ditch to suggest it was ever there. What we know of it amounts to a single cartographic appearance and then a silence.

A rath is a type of circular earthen enclosure, typically built in early medieval Ireland as a farmstead or defended settlement, defined by one or more raised banks and ditches. The Kilcooly example was recorded on the Ordnance Survey map of 1841 to 1842, which means surveyors considered it sufficiently legible at that point to merit marking. By the time the revised edition was produced in 1916, it had disappeared from the map entirely, and no surface trace has been identified since. Whether it was levelled for agriculture, eroded over decades, or simply misread on the earlier survey is unknown. What that gap of roughly seventy years between one map and the next represents in practical terms, whether gradual attrition or a more deliberate clearance, cannot now be determined from what remains.