Originally recorded by M.R. Calhoun, this earthwork was described as a substantial feature measuring approximately 100 feet from north to south and 56 feet from east to west. The northern end of the mound featured two small circles, and bones were discovered at the site, hinting at its possible significance as either a burial ground or ceremonial location.

Despite its intriguing description in historical records, the fort has proven remarkably elusive to modern researchers. When archaeologists attempted to relocate the feature for the Archaeological Survey of County Donegal in 1983, they found no trace of it amongst the rocky outcrops and pastures. The disappearance of such a sizeable earthwork raises questions; it may have been destroyed by agricultural activity, coastal erosion, or simply misidentified in earlier surveys.

The site represents one of many enigmatic monuments scattered across Donegal's landscape, where centuries of farming, weather, and development have altered or erased archaeological features. While the physical evidence may be lost, the historical record preserves tantalising details about this oval enclosure at Glenree, reminding us that Ireland's ancient past often lies hidden just beneath the surface, or in some cases, has vanished entirely into the realm of archaeological memory.