The operative word is "may". Local knowledge insists it is there, but the entrance has been closed up for safety reasons, and the ground above gives nothing away. No stonework breaks the surface, no hollow rings underfoot to the casual visitor. It is, in the most literal sense, an invisible monument.

The souterrain sits within a rath, the Irish term for a ringfort, a type of enclosed farmstead common across Ireland during the early medieval period, roughly the fifth to twelfth centuries. Souterrains were frequently built in association with these settlements, their underground galleries sometimes stretching for several metres, corbelled or lintelled in stone. The Rougham example is catalogued in the Archaeological Inventory of County Cork, though the record is candid about the limits of what is actually known: its existence rests on local tradition rather than excavation or visible evidence, and the act of sealing the entrance for safety has, in effect, preserved the uncertainty along with the site itself.