The Ordnance Survey recorded it in 1842, again in 1904, and once more in 1935, each time as a bivallate circular enclosure, meaning a roughly circular earthwork defined by two concentric banks and ditches, about thirty metres across. Local accounts described those banks as broad and well-defined. Then, sometime in the 1940s, they were levelled. Today there is no visible surface trace.

Ringforts, sometimes called raths, were the most common form of rural settlement in early medieval Ireland, typically serving as enclosed farmsteads for a single family and their livestock. The double-bank arrangement at Clashmorgan would have made it a more substantial example than the average single-vallate site. More intriguing still is the possibility of a souterrain in the interior. A souterrain is an underground passage or chamber, usually stone-lined, associated with ringforts across Ireland, and thought to have served for storage, refuge, or both. Whether any trace of that underground feature survived the levelling work of the 1940s is unknown.

What makes this site quietly strange is its persistence in the cartographic record across nearly a century, followed by its complete erasure from the landscape within a single decade. The maps document something the ground no longer confirms, leaving only the local memory of two fine broad banks and whatever may or may not lie beneath the grass.