What that name referred to is a souterrain, an underground stone-lined passage or chamber of the kind built in early medieval Ireland, typically as a place of storage, refuge, or concealment beneath or beside a settlement.

The structure had, by the time anyone looked closely at it, been lost to the landscape for long enough that land clearance works in 1996 were required to bring it back to light. Once uncovered, a survey of the monument was carried out, and access to the souterrain was subsequently closed off to prevent damage. The site sits in a townland whose name, Turlough, refers to a seasonal lake, a low-lying area that floods in winter and dries out in summer; such landscapes were often chosen by early communities precisely because their waterlogged nature offered a degree of natural protection.