At Lissavoura in County Cork, a ringfort once stood that is now knowable only through a single cartographic trace, a hachured circle on the Ordnance Survey six-inch map of 1842. Roughly twenty-five metres in diameter, it was recorded by the surveyors who criss-crossed Ireland in the early nineteenth century and captured the landscape before the railways arrived to reshape it. Today there is no visible surface trace whatsoever.

Ringforts, known in Irish as raths when defined by an earthen bank and ditch, were the most common form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the twelfth centuries. They served as enclosed farmsteads, with a circular earthen rampart protecting a household and its livestock. The Lissavoura example did not survive long after it was mapped. The construction of the Cork to Mallow railway line levelled the site entirely, leaving the 1842 OS map as its only documentary evidence. The timing makes the record bittersweet in a particular way: the same era of infrastructure and survey that preserved the knowledge of the fort's existence was also the era that destroyed it.