This one in Gibbonstown, County Limerick, does something rather different: it disappears. What is thought to be a ditch barrow, a type of prehistoric funerary monument typically consisting of a low central mound encircled by a surrounding ditch, leaves no trace at ground level that a visitor could point to or photograph. The only moment it has ever clearly shown itself was on a Google Earth orthoimage dated 5 April 2006, when it appeared as a circular cropmark, the kind of ghost-outline that buried archaeology sometimes produces in dry summers when grass above a filled ditch grows at a slightly different rate to the surrounding field. By the time the next detailed imagery was captured, between 2011 and 2013, it had gone quiet again.

The site sits in reclaimed pasture roughly twenty metres north of a stream that marks the boundary between Gibbonstown and the neighbouring townland of Fantstown. It belongs to a cluster of up to six possible barrows, recorded under references LI048-085 to LI048-090, concentrated within an area of approximately 175 by 100 metres in the southern part of the townland. That density is itself notable: barrows in Ireland were generally prehistoric burial monuments, and finding several in close proximity can suggest a small funerary landscape, a place communities returned to across generations. What makes the Gibbonstown examples particularly elusive is that none of them appear on the Ordnance Survey Ireland historic six-inch maps, the detailed nineteenth-century surveys that recorded a great deal of earthwork archaeology across the country. Their existence was only proposed after an oblique aerial photograph was taken on 5 January 2003, part of a programme of aerial survey that has transformed understanding of Irish archaeology by revealing features invisible at ground level. By April 2021, even satellite imagery showed nothing.

There is nothing to see here in any conventional sense, and that is rather the point. The site sits in working farmland, with no public monument, no marker, and no guarantee that the cropmark will reappear in any given year. Anyone with a serious interest in aerial archaeology might find it worth comparing the 2006 Google Earth imagery against current views of the field, noting how a monument that may be several thousand years old briefly surfaced through the medium of satellite photography and then went quiet. The stream boundary with Fantstown provides a rough orientation for locating the general area on a map. Beyond that, the record compiled by Martin Fitzpatrick and uploaded in September 2021 stands as the primary evidence, a monument more legible in an archive than in the ground beneath your feet.