At Woodbrook in County Galway, one such marking on the 1931 edition of the six-inch OS map turned out, when someone finally went to look in 1984, to be a disused gravel pit: an irregular hollow in the ground, quiet and unremarkable, left behind by the kind of small-scale extraction that once supplied road-making and building work across rural Ireland.

The pit is thought to date from the nineteenth or early twentieth century, a period when demand for locally sourced gravel was driven by the gradual improvement of roads and the construction of farm buildings and boundary walls. Operations like this were rarely documented in any formal way; they were practical, temporary, and forgotten almost as soon as the work moved on. What remains is simply the shape of the absence, a depression in the earth that the landscape has been slowly filling in ever since.