The earthwork consists of a roughly circular enclosure, measuring 13 metres across internally, defined by an earthen bank that appears to have been constructed by scraping up material from the hillside itself. Trees now grow along this defensive bank, their roots helping to preserve the ancient earthwork whilst adding a distinctive character to the site.

The fort's design includes what may have been two original entrances; gaps in the earthen rampart to both the east and west. These openings would have provided access to the enclosed interior space, which likely once contained timber buildings or other structures that have long since vanished. Such ringforts, known locally as raths, were common throughout Ireland during the early medieval period, typically serving as defended farmsteads for prosperous families between roughly 500 and 1200 AD.

The strategic positioning of this particular rath on the crest of Horse Hill was no accident. Its elevated location would have provided both defensive advantages and status, allowing its inhabitants to survey their lands and spot approaching visitors or threats from a considerable distance. Today, whilst the timber structures and bustling daily life have long disappeared, the earthwork remains as a tangible link to Donegal's medieval past, its tree-crowned banks still defining the same space that once sheltered an early Irish farming family.