On the 1930 edition of the Ordnance Survey six-inch map, a hachured marking near Oughtagh in County Galway suggested something worth noting, the kind of symbol that sends local historians and field surveyors down rough tracks in anticipation. When the site was inspected in 1984, the reality turned out to be more modest: a disused sand pit, sitting in rough pastureland with bogland stretching away to the west.