On a low hummock rising from the undulating pastureland near Ballyglass in County Galway, there sits a pit of ambiguous purpose, the kind of feature that rewards cartographic curiosity more than it satisfies it.

The story begins with a map. The 1947 to 1948 revision of the Ordnance Survey six-inch series recorded a hachured feature at this spot, a symbol typically used to indicate a depression or earthwork of some topographic significance. When someone finally went to look in 1984, the feature turned out to be a simple pit. Whether it was dug as a quarry, extracting stone or gravel from the hummock, or whether it served as a silage pit for agricultural storage, remains unresolved. Because the pit dates to after AD 1700, it falls outside the scope of prehistoric and early historic archaeology, which is why it occupies that quiet administrative category of things noted but not fully claimed by any particular discipline.