This one demands something harder: the ability to look at bare, quarried ground and imagine what is no longer there. On the western slope of a low hill near Moyne in County Galway, a ringfort once stood, a roughly circular earthen enclosure of around 40 metres in diameter. Ringforts were the most common form of rural settlement in early medieval Ireland, typically a farmstead enclosed by one or more earthen banks and ditches, home to a family and their livestock. This one has simply ceased to exist above ground.

The first edition of the Ordnance Survey six-inch map, produced in Ireland during the 1830s, recorded the enclosure clearly enough for it to be plotted and measured. By the time archaeologists came to document it in the late twentieth century, the hill had been extensively quarried and no visible surface trace survived. The site is known now only because a nineteenth-century cartographer thought to mark it, and because that mark was later followed up and found to lead to nothing.