For anyone consulting the 1931 edition of the Ordnance Survey six-inch map, these features appear as small hachured markings, the fine radiating lines cartographers used to suggest changes in relief or surface texture. They look, on the map at least, like something worth investigating.

When an inspection was carried out in 1984, the hollows turned out to be disused sand pits, most likely worked during the nineteenth or early twentieth century. Sand extraction on this scale was common in rural Ireland, where local pits supplied raw material for mortar, drainage work, and general construction without the expense or difficulty of hauling material from further afield. The pits at Cloonlyon are small and unspectacular, defined now only by the gentle depressions they left behind when the work stopped and the land around them settled back into agricultural use. What makes them worth a second glance is simply the gap between what the old map seemed to promise and what the ground actually delivered, a reminder that not every marked feature conceals something ancient or dramatic.