A rath, as this type of enclosure is known, was typically a circular or oval earthwork of banked earth and ditch used as a farmstead or settlement during the early medieval period, roughly between the fifth and twelfth centuries. Thousands survive across Ireland in various states of preservation. This one does not survive at all, at least not above the surface.

The first edition of the Ordnance Survey six-inch map, produced in the nineteenth century, shows an oval enclosure on a gentle west-facing slope, measuring approximately fifty metres by forty-five metres. That cartographic record is now the primary evidence that anything was ever here. At some point between the surveying of that map and the present day, whatever earthwork once defined the site was levelled entirely, absorbed back into the farmland around it. No banks, no ditches, no crop marks are mentioned. The landscape has closed over it.

What makes this worth noting is precisely the absence. The first edition OS maps captured Ireland's archaeological heritage at a particular moment in the mid-nineteenth century, and countless features recorded then have since disappeared to agriculture, development, or simple erosion. This site in Killeroran is one such casualty, known now only because a surveyor once drew a loop on a map and someone, much later, thought it worth recording what was no longer there.