A souterrain is an underground stone-lined passage or chamber, typically built during the early medieval period and associated with nearby ringforts, the circular enclosed settlements that were once the most common form of rural habitation across Ireland. This one is doubly invisible: not only is it underground, but the ringfort it belonged to has itself been levelled, leaving the landscape with no obvious clue that anything of archaeological significance lies beneath.

The sole historical reference to the structure comes from a 1937 mention of an "underground chamber" at the site. By the time the mid-Cork archaeological inventory was compiled, no visible surface trace of either the souterrain or the ringfort remained. That combination, a vanished enclosure and a subterranean chamber recorded only in an older source, makes Cloghboola More a particularly ghostly entry in the county's archaeological record. Ringforts were typically levelled by agricultural improvement, with field drainage, ploughing, and land clearance gradually erasing earthworks that had survived for over a thousand years. The souterrain beneath, sealed and forgotten, may well be intact; stone-lined underground chambers are often preserved precisely because they are out of reach of the machinery that destroyed what stood above them.

There is nothing for a visitor to observe at ground level, and no practical reason to seek the spot out. The interest here is less in the place itself than in what it represents: a category of site that exists primarily as an absence, known only because someone noted it down decades ago before the surface evidence disappeared entirely.