A rath, as this type of early medieval earthwork enclosure is known in Irish, would once have consisted of a roughly circular bank and ditch surrounding a farmstead or dwelling. The one at Boherduff has left no mark on the ground whatsoever. No earthwork, no depression, no ridge. Nothing.

What we know of it comes almost entirely from a single cartographic moment. When the Ordnance Survey produced its six-inch map series in 1838, the surveyors recorded a circular enclosure here, roughly seventeen metres in diameter, on a west-facing slope. A field boundary curved around it, running from the north-east through the east and around to the south-west, suggesting that whoever was farming the land at that time still recognised the outline of the old feature and respected it, at least partially, in the layout of their fields. By 1952, when McCaffrey catalogued it, the site had already receded from the physical landscape. Today, the pasture gives no indication that anything lies beneath.