Hachures, the short radiating lines cartographers use to suggest slopes or depressions in the landscape, can indicate all manner of things: a ringfort, a souterrain, a natural hollow. When someone went to look at this particular feature in 1984, it turned out to be a disused quarry, almost certainly worked at some point after 1700. The gap between the mark on the map and the knowledge of what it actually represented stretched nearly four decades.

The quarry's post-1700 date places it outside the scope of archaeological classification, which in Ireland generally concerns itself with features from earlier periods. That boundary is not a judgement on the site's interest so much as a practical administrative line. Quarries of this era were working features of rural life, dug to extract limestone or other local stone for building walls, roads, and structures on nearby farms and estates. They rarely attracted formal documentation. What Eskerboy has, then, is the quiet distinction of being a place that was mapped before it was understood, noticed as an anomaly before anyone confirmed what the anomaly was.