A souterrain is a man-made underground structure, typically built from drystone walling and roofed with large slabs, used for storage or refuge by early Irish farming communities. This one sits high on the hillside, with a wide view opening out over Bantry Bay to the north-west, a position that feels deliberate rather than incidental.

The entrance was filled with stones in relatively recent times to prevent animals from getting inside, a practical intervention that has, in effect, erased the most visible sign of what lies beneath. The mound that remains measures roughly ten feet east to west, twenty feet north to south, and stands about three feet high. These dimensions were recorded by Myler in a 1998 archaeological survey of the Mealagh Valley, which documented the site as part of a broader effort to catalogue the area's early remains. The valley, running inland from Bantry Bay in west Cork, contains a concentration of such features, many of them still easy to overlook precisely because they blend so thoroughly into the landscape.