On a low hillock in the pastureland of what was once Cregaclare Demesne in County Galway, something circular once stood, or was enclosed, or was defined by an earthen boundary. Nobody is entirely sure which. What is certain is that it has largely vanished.

The 1838 edition of the Ordnance Survey six-inch map recorded a circular feature here, roughly 45 metres in diameter, marked by a broken line, the cartographic convention for something approximate or partially visible even then. Over a century later, a researcher named McCaffrey catalogued it in 1952 with the cautious designation "Earthen fort (?)", the question mark doing considerable work. An earthen fort, or ringfort, was a type of enclosed farmstead common throughout early medieval Ireland, typically consisting of a raised circular area defined by one or more earthen banks and ditches, and used for habitation and the protection of livestock. Whether this site ever fitted that description, or represented something else entirely, remains unresolved. The broken line on the Victorian map suggests the surveyors themselves were uncertain of what they were looking at.

Today, the hillock is covered in scrub and no surface trace of the enclosure survives. It has become the kind of place that is easier to locate on a nineteenth-century map than in the actual landscape, which is, in its own way, a particular sort of archaeological condition: known, recorded, named, and gone.