The depression is unremarkable to the casual eye, but what it may conceal is anything but. A souterrain is an underground passage or chamber, typically stone-lined, built during the early medieval period in Ireland as a place of refuge, cool storage, or concealment. Most survive as dark, corbelled tunnels; this one, if local memory is correct, lies sealed beneath the turf.

The rath in which it sits is itself a significant structure. A rath, sometimes called a ringfort, is a roughly circular enclosure defined by an earthen bank and ditch, and was the most common form of rural settlement in early medieval Ireland, in use broadly from the fifth to the twelfth century. Souterrains are frequently associated with raths, often positioned within the interior of the enclosure, where they could be accessed discreetly. The roughly circular form of the depression at Liscluman, and its placement within the rath rather than outside it, is consistent with that pattern. Whether the passage below, if it exists, remains intact is unknown; the site appears to have been blocked rather than excavated, leaving what lies beneath a matter of tradition as much as archaeology.