With an internal diameter of 15.6 metres, this ancient ringfort represents one of Ireland’s many stone fortifications, likely built during the early medieval period when such structures dotted the landscape. Despite centuries of weathering and partial collapse, the drystone walls still stand up to 1.6 metres high in places, offering visitors a tangible connection to the area’s distant past.

The cashel’s most intriguing feature is a mural passage that runs through the wall from the east-northeast to northeast sections, extending for approximately six metres. This corridor, constructed with the same drystone technique as the main walls, was originally roofed with flagstones, several of which remain in their original positions. Though now filled with collapsed stone and reaching only 0.8 metres in height at its tallest points, the passage would have served as a secondary access point or perhaps a defensive feature. The main entrance, measuring 1.4 metres wide, faces southeast; a typical orientation that would have provided the inhabitants with optimal light and shelter from prevailing winds.

Today, the site presents challenges for visitors, as trees and scrub have overtaken much of the surrounding area, and the boggy conditions make access difficult. This overgrown state, whilst hampering archaeological study, has perhaps helped preserve the structure by protecting it from more intensive agricultural use. The cashel stands as part of a broader archaeological landscape documented in the comprehensive 1983 Archaeological Survey of County Donegal, which catalogued field antiquities from the Mesolithic period through to the 17th century, ensuring that sites like this one at Doon Glebe remain part of Ireland’s recorded heritage.