It leaves no mark on the surface, no depression in the grass, no tumble of stones to suggest its presence. It simply sits there, silent and sealed, in the south-eastern corner of a ringfort whose own earthworks are the only outward clue that something deliberate once happened here.

A souterrain is an underground passage or chamber, typically built during the early medieval period in Ireland, constructed from stone and roofed with large flat slabs called lintels. They are found in their hundreds across the country, often tucked within or beside ringforts, the circular enclosed settlements that were the dominant form of rural habitation between roughly the sixth and twelfth centuries. Their precise function is still debated; cool storage, refuge, or both are the most common explanations. The one at Meenahony was recorded in 1939 by P. J. Hartnett, who described a single chamber, oblong in plan, with its lintel roof intact at the time of his visit. That published account remains the primary record of what lies below ground. Whether the chamber is still structurally sound, or whether the centuries since Hartnett's note have taken any toll on it, is not known from the available record.

What is certain is that there is nothing to see at ground level. The souterrain has no visible surface trace, which means any visit to the area would be shaped entirely by knowledge of the ringfort rather than by anything the eye can immediately detect.