Only a small portion of the western side of the enclosing bank remains standing, reaching an internal height of 1.75 metres. This surviving section reveals the fort's construction method; primarily built from earth with some stone incorporated into the structure, a common building technique for these defensive settlements.

The location of this ancient fortification was carefully chosen, positioned on elevated ground above the river valley in what would have been prime agricultural land. Ringforts like this one were the predominant form of rural settlement in Ireland from the early medieval period, typically dating from around 500 to 1100 AD. They served as protected homesteads for farming families, with the circular bank and ditch providing security for both people and livestock.

Though much of the structure has been lost to time, what remains at Breenagh offers a glimpse into how our ancestors organised their lives and defended their communities. The site was documented as part of the comprehensive Archaeological Survey of County Donegal, conducted in 1983, which catalogued field antiquities from the Mesolithic period through to the 17th century. Even in its ruined state, this modest earthwork stands as a tangible connection to the everyday lives of medieval Irish farmers who once called this ridge home.