The label implies something underground, something old, something worth distinguishing from the surrounding farmland. On the ground today, however, there is no obvious cave to be found, and the souterrain that a 1977 map by Robinson indicated here has left no clear trace above the surface.

A souterrain is an underground passage or chamber, typically stone-lined, built during the early medieval period in Ireland and used variously for storage, refuge, or ventilation of adjacent structures. Whether one genuinely lies beneath this patch of ground in Ballyvoe is now difficult to confirm. What is visible is an overgrown area of roughly six metres by six metres beside a pond, where large limestone slabs and smaller stones emerge intermittently from the vegetation. The site sits on a slight rise within a relict field system, itself embedded within a larger, multi-period field system, suggesting that people have been working and dividing this land across many centuries. The limestone slabs may be the displaced or collapsed remnants of a stone-roofed underground structure, or they may not. The record is inconclusive, and that inconclusiveness is itself part of the interest. Several hollows about a metre across were observed at the site, though their current occupants are badgers rather than archaeologists.

The place exists in a quiet suspension between designation and uncertainty, named on maps for nearly two centuries, flagged as an antiquity, and yet resistant to easy interpretation. The Gothic lettering on those old OS sheets carries a confidence the landscape no longer quite supports.