The Ordnance Survey maps mark a circular enclosure here, the footprint of an early medieval ringfort or rath, yet nothing visible remains on the ground today. What makes this site particularly interesting is not what has survived but what local memory has preserved: the knowledge that a souterrain once ran beneath it.

A souterrain is an underground stone-lined passage, typically associated with ringforts and used in early medieval Ireland for storage, refuge, or both. At Teernahila, local information recorded by archaeologists A. O'Sullivan and J. Sheehan in their 1996 survey of the Iveragh Peninsula describes a stone-built souterrain passage that was filled in many years before their work was compiled. The enclosure itself has left no surface trace. What survives, then, is a map reference, a community memory, and a set of coordinates pointing to a hillside where, at some point in the early medieval period, people built a defended homestead, dug or constructed a hidden underground passage beneath it, and eventually abandoned both to time and later land use.

There is nothing to see at Teernahila in the conventional sense, which is itself worth sitting with. Many of Ireland's archaeological sites are known only through the paper record and the recollections of local people who noticed something, remembered something, or were told something by an older generation. The filled-in souterrain at Teernahila is one small example of how much of the early medieval landscape has been quietly erased, leaving only a circle on an old map and a story that almost did not get written down at all.