That combination, an underground passage still intact while the earthwork enclosing it has been swallowed by scrub and growth, gives the site a particular character: the subterranean part survives while the surface context has become almost illegible.

Souterrains are stone-lined underground passages or chambers, built during the early medieval period, typically within or beside ringforts. Ringforts themselves, circular enclosures defined by earthen banks or stone walls, were the most common form of rural settlement in Ireland from roughly the sixth to the twelfth centuries. Souterrains associated with them were likely used for cold storage, refuge, or both, their narrow, dark interiors remaining cool year-round. At Keenrath, local tradition has long maintained the existence of such a passage, and that tradition appears to hold: the souterrain is recorded as still open. What the ringfort that contains it once looked like at ground level is now difficult to say, the interior being too overgrown to inspect properly.