Ringfort (Rath), Ballynagowan, Co. Limerick

It is a rath, the Irish term for a ringfort, which was the most common type of rural settlement in early medieval Ireland. Typically constructed between roughly 500 and 1000 AD, ringforts were enclosed farmsteads, their earthen banks and ditches defining a household's space rather than serving any serious military purpose. This one at Ballynagowan is modest in scale and, until 2013, absent from the official record.

The site came to light not through a ground survey or a chance discovery by a walker, but through lidar, a remote-sensing technology that fires pulses of laser light from an aircraft and measures the returning signals to build up a detailed model of the ground surface beneath vegetation and soil. It was Paul O'Keeffe, an Assistant Archaeologist with the National Roads Authority, who identified the enclosure on a lidar image produced as part of the Leinster Statewide Roads Review, and he reported it to the Archaeological Survey of Ireland on 8 March 2013. The record was compiled by Denis Power and uploaded to the survey database a week later. The episode is a small illustration of how systematically gathered aerial data continues to add to the known corpus of Irish field monuments, pulling features into view that centuries of occupation and landscape change had left unnoticed.

Because the site entered the record so recently and the available notes contain no description of surface visibility or access, it would be worth consulting the National Monuments Service mapping viewer before visiting, which allows you to locate recorded monuments by townland and cross-reference them against modern satellite imagery. The enclosure is in the townland of Ballynagowan, and lidar-identified sites can sometimes appear as very faint earthworks, a slight rise or a subtle curve in a field edge, rather than the dramatic banks a visitor might expect from a more prominent ringfort. If the surrounding land is under grass rather than tillage, the circular outline may be easier to read from an elevated position nearby than from ground level.