Somewhere in the pasture at the south-western edge of a plateau near Boolabeg, a ringfort exists that cannot actually be seen from ground level. That is a quietly disorienting fact. Ringforts, the circular enclosed settlements built across Ireland primarily during the early medieval period, are usually among the more legible features of the Irish countryside, their raised banks and ditches catching the low light of a winter afternoon. This one, by contrast, has sunk so thoroughly into the landscape that a person could walk across it without any awareness of what lay beneath their feet.

What makes the site stranger still is the discrepancy recorded between two editions of the Ordnance Survey six-inch maps. When the surveyors visited in 1840, they noted a circular embanked enclosure with an external diameter of approximately 35 metres. By the time the same maps were revised in 1927, that recorded diameter had grown to approximately 50 metres. Whether this reflects a genuine difference in measurement, a change in what was visible on the surface, or simply a variation in how the two survey teams defined the enclosure's outer edge is not clear. The gap of nearly a third as much again is large enough to raise the question, even if the notes left behind offer no answer to it.