At Rosmore in County Galway, a feature carefully recorded on the 1948 revision of the Ordnance Survey six-inch map had left no visible trace whatsoever by the time anyone went to look for it on the ground. When the site was inspected in 1983, cleared pastureland was all that remained, with nothing to suggest that anything had ever broken the surface there at all.

The original map showed a hachured feature, meaning it was represented by short radiating lines used by cartographers to indicate a depression or hollow in the terrain. Whether that depression was entirely natural or the result of human activity was never definitively settled. The working interpretation is that it was most likely a quarry pit, a small extractive hollow of the kind that was once common across this part of Galway, dug to supply local stone for building, road repair, or field boundary work. Such pits were practical, informal, and often short-lived, backfilled or simply left to collapse and grass over once the immediate need had passed. Decades of agricultural clearance would have done the rest, smoothing out whatever contour had once been noticeable enough to catch a surveyor's eye.