At Blindwell in County Galway, a circular enclosure roughly forty metres in diameter was recorded on the first edition of the Ordnance Survey six-inch map, drawn up in the nineteenth century, yet today the ground gives nothing away. Level grassland stretches across the site without so much as a faint depression or a raised bank to suggest that anything was ever there.

Circular enclosures of this kind are generally understood to be the remains of ringforts, the enclosed farmsteads that were the most common settlement type in early medieval Ireland, typically dating from around the sixth to the twelfth century. They were usually defined by one or more earthen banks and ditches, sometimes topped with a timber palisade, and they served as both a domestic space and a means of protecting livestock. A diameter of around forty metres is fairly typical. What the Ordnance Survey cartographers recorded at Blindwell was evidently still legible in the landscape when they passed through, which makes its complete disappearance since then all the more striking. Centuries of ploughing, drainage work, or simple agricultural levelling can erase even a substantial earthwork, leaving only the map as a witness.