On the earlier map, the site is marked simply as 'Fort', a word the early surveyors used to indicate an earthwork of the kind commonly known as a rath. By the time the cartographers returned four decades later, that confident label had softened into 'Site of', which in the language of nineteenth-century mapping is a small but telling demotion, suggesting that whatever had been visible on the ground was no longer there.

A rath is a circular earthen enclosure, typically defined by one or more banks and ditches, built during the early medieval period in Ireland as a farmstead or settlement for a family of some local standing. Thousands survive across the country in varying states of preservation, though many more have been levelled by centuries of agriculture. At Beagh Glebe, the site sits on a low rise in the landscape, the kind of gentle elevation that would have made practical sense to a farmer seeking dry ground and a clear view of the surrounding land. Today nothing is visible at ground level; the earthworks, if any remained into the modern period, have been absorbed entirely into the surrounding terrain.