A cashel is a dry-stone ringfort, a type of early medieval enclosure common across Ireland, and souterrains, the underground stone-lined passages sometimes found within them, were likely used for cool storage or as places of refuge. The one at Clogherane exists, so far as archaeology is concerned, almost entirely as a rumour.

The basis for its inclusion in the record is local tradition rather than excavation or survey. According to information gathered from people in the area, a stone-roofed underground passage once existed within this cashel and was closed up at some point in the past. No visible trace of it remains at the surface. It is the kind of entry that sits in an inventory as a question mark, neither confirmed nor dismissed, kept alive because local memory of such things is often older and more reliable than it appears, and because the cashel itself is a real and recorded structure.