One such entry is a feature recorded simply as a circle of five dots on the Ordnance Survey twenty-five-inch plan surveyed in 1910, sitting immediately south of a field boundary. By the time of the 1940 revision, cartographers had given it a name, "Megalithic Structure", though the Name Book accompanying that revision offers only a tentative description: four stones forming a half circle.

The discrepancy between the map's five dots and the Name Book's four stones is itself telling. Whether this reflects stones lost in the intervening thirty years, an error of observation, or simply the difficulty of reading a low and fragmentary arrangement in the field is impossible to say now. What is certain is that the antiquary George Petrie, who worked extensively in Ireland in the nineteenth century, never noted the feature at all, and today there is no visible trace of it on the ground. The assessment is frank: its nature is uncertain, and it may well have been entirely natural, perhaps a chance grouping of glacial erratics that happened to suggest human intention to a surveyor's eye in 1910 and again, at least partially, in 1940.