Ringfort (Rath), Rossilly, Co. Donegal

The site consists of a subcircular enclosure measuring approximately 35 metres in internal diameter, protected by three distinct features: an inner earthen bank, a surrounding fosse (defensive ditch), and an outer bank. The fort's builders cleverly exploited the natural shoulder of the hill to enhance both the height of the inner bank and the depth of the fosse, creating what appears to be a raised interior platform; a common defensive strategy that would have made the site more imposing to potential attackers.

The northern side of the ringfort has been modified over the centuries, incorporated into a field boundary that gives the entire structure a distinctive D-shaped plan when viewed from above. This adaptation speaks to the site's continued relevance in the landscape long after its original defensive purpose had passed. The choice of location was strategic; whilst the drumlin itself provided good, fertile land for agriculture and settlement, its low-lying position meant it could be naturally defended when tidal flooding turned the marshy ground at its base into a temporary moat, effectively transforming it into an island fortress.

This description draws from the comprehensive Archaeological Survey of County Donegal, compiled by Brian Lacey and colleagues in 1983, which catalogued field antiquities from the Mesolithic period through to the 17th century. The survey has been subsequently revised and updated, most recently in September 2008, ensuring that our understanding of sites like this Rossilly ringfort continues to evolve with new archaeological insights and research methods.