At Hillswood in County Galway, a rectangular enclosure measuring roughly 35 metres by 30 metres was recorded on the first edition of the Ordnance Survey six-inch map, the great nineteenth-century cartographic project that documented Ireland field by field. Today, in the low-lying farmland where it once stood, there is nothing to see at all. No earthwork, no crop mark visible to the passing eye, no slight rise in the ground. The enclosure has been erased, or perhaps absorbed, by centuries of agricultural activity.

Enclosures of this kind were a common feature of the Irish landscape, serving any number of purposes depending on their period and context: the ringfort tradition of early medieval settlement produced thousands of circular and occasionally rectangular examples across the country, used as farmsteads or for the enclosure of livestock. Whether the Hillswood example belongs to that tradition or to some other, earlier or later, use of the land is not recorded. What is known is that by the time the Ordnance Survey mappers passed through, it was sufficiently visible to be worth marking. At some point between that survey and the present, it ceased to be visible at all.