At the south-western end of a glacial ridge in the pastureland of Gallagh, Co. Galway, there is an overgrown rectangular hollow, the kind of subtle depression that the untrained eye might walk past without a second thought. On the 1932 edition of the Ordnance Survey six-inch map, this feature was recorded using hachuring, a draughting technique that uses short lines to indicate changes in relief or the outline of earthworks, which in an archaeological context might suggest an ancient enclosure or feature of some antiquity. When the site was inspected in 1983, however, it turned out to be a disused sand or gravel pit, almost certainly dug after 1700.

The glacial ridge on which it sits is itself a remnant of the last ice age, a low landform deposited as glaciers retreated and left behind unsorted material, including the kinds of sand and gravel that would have made such a pit commercially useful in later centuries. The pit was almost certainly worked for building or road materials at some point during the eighteenth or nineteenth century, a common enough local practice that left similar hollows across the Irish countryside. By the time anyone looked closely at this one, it had softened back into the landscape, its edges blurred by grass and vegetation, its origin only legible if you knew what you were looking for.