Souterrains are underground passages or chambers, typically constructed during the early medieval period in Ireland, and their precise purpose has long been debated. Refuge, cold storage, and escape route are the most commonly suggested functions, and they may well have served all three at different moments.

The souterrain sits within a ringfort, the circular enclosure that was the standard unit of rural settlement in early medieval Ireland, typically dating from roughly the seventh to the twelfth century. Ringforts varied considerably in scale and complexity, from simple single-bank enclosures to more elaborate examples with multiple ditches and internal features. The presence of a souterrain within one is not unusual in itself, but each surviving example preserves something of the texture of daily life and its anxieties in that period. At Rathaneague, the construction is in sandstone, a material local to much of Cork, shaped into blocks that have held their position long enough to become part of the landscape rather than an interruption of it.