The site at Caherroyn is one of those places that has effectively vanished from the landscape, surviving now only as an ink circle on a map drawn nearly two centuries ago. Its name, derived from the Irish "cathair", referring to a stone-walled circular enclosure typically used as a fortified farmstead in early medieval Ireland, is the most substantial thing left of it.

The 1838 edition of the Ordnance Survey six-inch map recorded a circular enclosure here, approximately 35 metres in diameter. That survey, one of the most ambitious cartographic projects of nineteenth-century Ireland, captured the landscape at a moment before the great infrastructural upheavals of the Victorian era reshaped it. The Galway to Dublin railway line, which cuts across the site from roughly north-east to south-west, is the most likely cause of the enclosure's disappearance. The construction of that line, threading through the Irish midlands and into Connacht, would have required substantial earthworks, and a low earthen or stone ring in its path would have offered little resistance to the navvies and their equipment. No visible surface trace survives today.