It is the surviving remnant of a souterrain, an underground stone-lined passage or chamber built during the early medieval period, typically associated with nearby settlement sites and used for food storage, refuge, or both. What can be seen today is a small opening, and even that is a diminished version of what was once there.

Local knowledge holds that the original structure was considerably larger, but successive collapse has caused the interior to infill over time until only this modest pocket of space remains. The stream visible below the slope would have made the location practical for whoever built and used the souterrain, providing both water and a natural landmark for a farming community that may have occupied this ground over a thousand years ago. No excavation appears to have taken place here, so the full extent of what lies beneath the field, or what it might once have connected to, remains unknown.

The site is recorded as inaccessible, and the opening into the cavity is too small and too unstable to enter safely. What draws attention here is less the souterrain itself, which is largely gone, and more the fact that such a structure persists at all, quietly collapsing under a working field in mid Cork, unexcavated and largely unexamined.