A souterrain is an underground stone-lined passage, typically associated with early medieval settlement in Ireland, used variously for storage, refuge, or both, and often built as an integral part of the enclosed farmstead above it. In this case, the structure sits within a rath, the earthen ringfort that once defined the boundaries of a farming household, probably dating to the early medieval period. When surveyors came to examine it in 1982, they found the entrance blocked up, leaving whatever the passage contained undisturbed.

The site has a paper trail that runs back almost two centuries. It appears on the first edition of the Ordnance Survey maps, produced in 1838, and was still being marked on the third edition in 1922, which suggests it remained a recognisable feature of the landscape across that span of time. The "Caves" of the place name almost certainly refers to this souterrain, a local naming convention common across Ireland wherever such passages were known to exist but not well understood. The monument is protected under the National Monuments Acts, with a preservation order dating from 1984, meaning any interference with the site is a legal matter rather than merely an archaeological concern.