The structure measures approximately 33 metres north to south and 27 metres east to west, and it is the kind of thing that becomes visible only when you know to look, having been identified from satellite imagery rather than ground survey. It is a possible cashel, the term used for a ringfort built primarily from stone rather than earthen banks, a form of enclosed farmstead typical of early medieval Ireland in which a family and their livestock would have lived and worked within a defensive perimeter wall.

The site came to wider attention when Lynda McCormack reported it to the National Monuments Service, having spotted it on Digital Globe imagery captured between 2011 and 2013. What makes it particularly interesting is not the enclosure alone but its relationship to the surrounding landscape. Field walls appear to radiate outward from the cashel itself, and these are considered likely contemporary with the main structure, suggesting the enclosure was the organising centre of a working agricultural system rather than an isolated fortification. That system sits within a much larger multiperiod field complex, meaning the land around it carries traces of occupation and land use from several different eras layered one over another. Adding further depth to the picture, a second cashel lies just 25 metres to the north-west, raising the possibility that this corner of Rannagh once supported more than one household operating in close proximity across the same farmed ground.