A semicircular arc of earthen bank, roughly 25.5 metres across its north-south span and standing about 1.1 metres high, curves through pasture on the western side of the Carrigduff River. The eastern half of the enclosure is simply gone, levelled at some point before the early twentieth century, and what remains has been quietly absorbed into the surrounding field fence system, its original purpose all but dissolved into the everyday geometry of farmland.

Ringforts, known in Irish as raths when formed from earthen banks rather than stone, were the most common form of rural settlement in early medieval Ireland, typically dating from roughly the fifth to the twelfth centuries. They served as enclosed homesteads, the circular bank and ditch protecting a household and its animals. The Horsemount example was recorded on the Ordnance Survey six-inch map of 1842 as a hachured circular enclosure with a diameter of around 18 metres, which puts it at the modest end of the scale. By the time the same survey was revised in 1904, the eastern half had already been levelled, leaving only the arc visible today. That the remaining bank has since been incorporated into the field boundary is a reminder of how often these structures have survived not through deliberate preservation but simply because a farmer found them useful as a ready-made fence line. The bank itself is now heavily overgrown, its profile softened by vegetation.