It is, in fact, a rath, the Irish term for a ringfort, and one of thousands of such enclosures scattered across the Irish countryside. Ringforts were typically built during the early medieval period, roughly between the fifth and twelfth centuries, and served as enclosed farmsteads, the scarped or embanked perimeter defining a family's living space and offering some protection for livestock. At Clashganniff, that perimeter is still legible in the land, if you know how to read it.

The site was recorded by Denis Power and uploaded to the survey record in August 2011. The enclosure measures approximately 31 metres north to south and 29.7 metres east to west, making it a modest but reasonably proportioned example of the type. Its defining feature is a scarped edge, that is, a slope cut or worn into the ground to create a visible boundary, running from the south-west around to the north-east. The scarp is best preserved at the north-north-east, where it reaches a height of around 0.8 metres and a width of 5.5 metres. Moving south-west and north-west, it reduces to roughly 0.3 metres. A field boundary, probably a later addition, runs across the north-east to south-west line at a height of 0.75 metres, partially overlying and obscuring the original scarp at that point. The interior is level and sits under rough pasture.

The site sits in working farmland, so access is not guaranteed without landowner permission. The ridge location means the enclosure is slightly elevated above its surroundings, which helps in picking out the scarp from the surrounding ground level. The north-north-east arc, being the most pronounced, is the logical place to start when trying to trace the circuit. Winter or early spring, when vegetation is low and the angle of light is oblique, generally makes earthwork detail easier to see. The overlying field boundary on the north-east side complicates the reading of the scarp in that section, but the overall circular form of the enclosure can still be followed with patience.