A souterrain is an artificial underground chamber or tunnel, typically constructed during the early medieval period in Ireland, built from dry-stone walling and roofed with large flat stones. They were dug into the earth beside settlements, almost certainly serving as places of refuge, cool storage for dairy produce, or both. Hundreds survive across Ireland, many still unexcavated, and the one at Tawlaght belongs to that largely anonymous company.

Beyond its classification and location, the specific details of this particular souterrain, its dimensions, its condition, the precise date of its construction, and any finds or features associated with it, are not yet in the public record in any accessible form. Kerry as a county has a remarkable density of early medieval archaeology, and souterrains in the south-west often appear in close association with ringforts, the circular enclosed farmsteads that were the dominant settlement type of the period roughly between the fifth and twelfth centuries. Whether that pattern holds at Tawlaght remains, for now, an open question.