Ringfort (Cashel), Castlethird, Co. Donegal
On the southeastern slope of Dooish mountain in Castlethird, County Donegal, sits the remains of a stone ringfort, or cashel, that once stood as a formidable defensive structure.
Ringfort (Cashel), Castlethird, Co. Donegal
This subcircular enclosure measures 19 metres across its interior and would have served as a fortified homestead during Ireland’s early medieval period. Though time has taken its toll on the monument, the collapsed stone walls have been partially rebuilt along the southern and western sides, offering visitors a glimpse of its original form. The scatter of fallen stones extends outward for up to 5.5 metres on the southwest side, testament to the substantial nature of the original construction.
The cashel occupies what would have been considered prime agricultural land, strategically positioned on the mountain slope with good views of the surrounding countryside. Today, lanes run alongside the eastern and northern boundaries of the site, providing access whilst the interior has become heavily overgrown with vegetation. These stone forts were typically built between the 5th and 12th centuries AD and served as the defended farmsteads of prosperous families, combining residential, agricultural, and defensive functions within their sturdy walls.
This particular site was documented as part of the comprehensive Archaeological Survey of County Donegal, compiled by Brian Lacey and his team in 1983. The survey catalogued field antiquities spanning from the Mesolithic period through to the 17th century, creating an invaluable record of Donegal’s archaeological heritage. Like many such monuments across Ireland, this cashel stands as a tangible link to the county’s early medieval past, when such fortified homesteads dotted the landscape and local chieftains held sway over their territories.





