That description comes from Ashe, writing in 1954, and it is the kind of phrase that tends to lodge in the mind. Souterrains, stone-lined underground tunnels typically associated with early Irish ringforts, were built for storage, refuge, or both, and they range from simple single chambers to branching networks. The one at Ballintermon appears to belong firmly to the latter category.

The site sits within a univallate rath, meaning a ringfort enclosed by a single earthen bank and ditch, roughly 31.5 metres in diameter east to west. It occupies a fairly level stretch of ground with views across the Anascaul valley to the north-west, the kind of position that would have suited a farming family of the early medieval period who wanted both good land and a watchful eye on the surrounding landscape. The entrance to the souterrain is marked today by a small depression just inside the western bank, the ground having settled or collapsed slightly over the centuries above whatever passage lies beneath. J. Cuppage documented the site in the 1986 Dingle Peninsula archaeological survey, drawing on earlier observations including Ashe's account of the underground network below.