When surveyors examined a feature of this kind at Garrafine in County Galway in 1983, working from the 1932 edition of the six-inch OS map, what they found was a disused gravel pit, densely overgrown and sitting quietly in the middle of pastureland. Not ancient, not mysterious, but sufficiently ambiguous on paper to warrant a closer look half a century after the map was drawn.

The pit dates to after 1700, which places it outside the scope of archaeological classification, and so it passed into a kind of administrative limbo, noted and then set aside. Gravel pits of this era were a practical feature of the rural Irish landscape, dug to supply material for road-making and farm tracks, then abandoned once the immediate need was met. Nature moved in quickly, as it tends to in the damp west of Ireland, and by the time anyone came to look properly, the ground had largely reclaimed it.