The Ordnance Survey six-inch map of 1838 already showed Turin Roman Catholic Chapel occupying the eastern quadrant of the fort, and the ground today confirms what that early cartography suggested: the chapel grounds have physically removed the perimeter bank and part of the interior across the northeastern to southeastern arc of the monument.

Ringforts, also known as raths, are roughly circular enclosures defined by an earthen bank and an outer ditch, and they were the most common form of farmstead in early medieval Ireland, typically dating from somewhere between the sixth and tenth centuries. At Tevrin, the sub-circular enclosure measures approximately 42 metres across on its northwest to southeast axis. The surrounding bank survives to about 1.2 metres in height in places, though it is fragmentary for much of its circuit, and the external fosse, a shallow defensive ditch, is best preserved along the southwestern to western stretch. Inside, the level interior holds traces of four possible hut sites and what appears to be a collapsed souterrain, an underground stone-lined passage that was commonly used in early medieval Ireland for storage or concealment. A field fence cuts across the western perimeter, adding a more recent layer of disruption to a monument already altered by centuries of use. A stream running roughly 35 metres to the south marks the boundary with the neighbouring townland of Killynan, placing the fort at a position that would have been meaningful in terms of landholding long before the chapel arrived to complicate the picture.