No earthwork, no ditch, no raised bank survives at ground level; the field is pasture, and to walk across it is to find nothing at all. Yet the site carries a formal archaeological designation, because something was once recorded here, even if the physical evidence has long since vanished beneath centuries of agricultural use.

A rath is a type of early medieval enclosure, typically defined by one or more circular earthen banks and ditches, used as a farmstead or place of habitation. What makes the Tonyellida example particularly elusive is its paper trail. Two adjoining enclosures were marked at this location on McCrea's map of County Monaghan, drawn in 1793. That cartographic record is essentially the only evidence for the site's existence, since neither enclosure appears on any subsequent map. The precise location of the western of the two features is no longer known at all. It is a rare situation in which the map itself becomes the primary archaeological document, and the landscape it was meant to describe has become unreadable.