The rath measures approximately 45.5 metres east to west and 39 metres north to south, and is defined by two concentric banks with a fosse, a cut or dug ditch, running between them. That double-bank arrangement is worth noting: while single-banked raths are the most common form of early medieval enclosure in Ireland, the extra circuit here may have signalled a household of some social standing, since the effort required to throw up a second bank was considerable. The entrance gap opens to the north, which is slightly unusual given that southern or eastern orientations are more frequently recorded at such sites.

Raths of this kind were the farmsteads of early medieval Ireland, occupied roughly between the fifth and twelfth centuries, though many continued in use or were adapted long after that period ended. They functioned as enclosed homesteads, protecting livestock and people alike, and they survive in their thousands across the Irish countryside, often repurposed or quietly absorbed into the working farm landscape. At Clashaganny, that absorption is visible in two field walls that cut across the monument, one passing through the earthwork at the north-north-east and south-south-west, another overlying the outer bank between the south-south-east and south-west. The walls belong to a later agricultural reorganisation of the land, their lines indifferent to what lay beneath them. Within the interior, a souterrain has also been recorded, an underground stone-lined passage associated with early medieval settlement, typically used for storage or as a place of refuge.