The Ordnance Survey's 1947 to 1948 revision of its six-inch map showed a hachured marking at this spot, the kind of cartographic shorthand used to indicate a rise, hollow, or earthwork of some potential interest. When someone finally went to look in 1984, the reality was considerably more modest: a disused sand pit, dug at some point after 1700 and long since abandoned to the grass and the weather.

There is a particular kind of minor anticlimax that runs through the history of field survey work, and this site captures it neatly. A mark on a map, made by someone decades earlier who may themselves have been uncertain what they were recording, sits quietly in an archive until a surveyor goes to check. The sand pit at Coolfin almost certainly served some local, practical purpose, the kind of small-scale extraction that was common across rural Ireland for building, drainage, or land improvement. Because it dates to after AD 1700, it falls outside the scope of archaeological classification, which generally concerns itself with earlier remains, and so the site exists in a slight administrative no-man's-land, noted but not catalogued as heritage in any formal sense.