Near Ballylongford in north Kerry, the ground holds no visible trace of a ringfort that was still mappable in the nineteenth century, leaving behind little more than a name and a cartographic ghost.

The site is recorded in Irish as Lios Ruairí, meaning the ringfort of Ruairí, a personal name equivalent to the anglicised Rory. A ringfort, or rath, is a circular enclosure defined by one or more earthen banks and ditches, typically dating from the early medieval period and used as a farmstead or residence. This one was classed as univallate, meaning it had a single enclosing bank. When the Ordnance Survey mapped the area in 1841 and 1842, the rath was still legible in the landscape. By the time a later edition was produced, it had been reduced to a semicircular enclosure, with the Glashanagalloon stream cutting directly through the site before draining into Ballylongford Creek. Erosion, land use, and the persistent work of water had done their slow work. A subsequent field survey found no surface trace remaining at all.

What survives is the place-name itself, which is often the most durable thing about a vanished monument. The Irish naming convention for ringforts frequently preserves the identity of an early medieval landowner or family, and Lios Ruairí is a typical example: a personal name attached to a landform, carrying forward the memory of an individual whose fort the stream has long since swallowed.