At Rathkenny in County Kerry, a ringfort, the kind of circular earthen enclosure that once served as a farmstead or minor defended residence during early medieval Ireland, once occupied the ground here clearly enough to be plotted by cartographers on not one but two successive Ordnance Survey maps. Today, no surface trace of it survives at all.

The site appears on the OS maps of 1841 to 1842 and again on the 1898 revision, each time recorded as a circular enclosure, which is the characteristic form of a rath, a ringfort defined by one or more banks and ditches thrown up around a central living area. That it was still visible to surveyors at the end of the nineteenth century, yet has since been entirely levelled, points to clearance during the agricultural intensification of the twentieth century, a fate that claimed a considerable number of such sites across Ireland. What survives is essentially cartographic: the memory of a boundary line, the ghost of a circle on old paper.