A rath, as these earthwork enclosures are generally known in Irish usage, was a roughly circular farmstead of the early medieval period, defined by one or more banks of thrown-up soil and, usually, an outer ditch. Thousands once dotted the Irish landscape, though agriculture has quietly erased a great many of them over the centuries.

The site appears on the Ordnance Survey maps of 1841 to 1842 as a circular enclosure, with something notable marked in its interior: the word 'cave', indicating a souterrain, an underground stone-lined passage typically associated with ringforts and used for storage or, in extremis, concealment. By the time the next mapped edition was produced in 1915 to 1916, that annotation had disappeared, suggesting the feature may have already been disturbed or forgotten in the intervening decades. The enclosure itself has since been almost entirely levelled, the result of agricultural clearance. Only the north-western arc of the enclosing bank remains, and it does so only because it was absorbed into an existing field boundary, which gave it just enough practical purpose to escape the same fate as the rest.

The distinction between what the old maps recorded and what now exists on the ground is precisely what makes Knoppoge worth thinking about. The souterrain reference alone, now unverifiable in the field without excavation, hints at a more complex site than a simple enclosure. That a small section of bank persists at all is more accident than preservation, folded into the landscape in the most unremarkable way possible.