A souterrain, to give it its proper name, is an artificial tunnel or chamber, typically built during the early medieval period in Ireland, roughly between the seventh and twelfth centuries. They were constructed from drystone walling and roofed with large capstones, and their purpose is still debated: cold storage, refuge, or simply an escape route from a settlement under threat. What makes them quietly compelling is how ordinary the landscape above them can appear, with no obvious surface feature to betray what lies beneath.

The souterrain at Lissodeige is recorded as a known monument in County Kerry, a county with no shortage of early medieval activity, though detailed documentation for this particular site has not yet been made publicly available. Kerry's landscape preserves an unusually dense concentration of early medieval remains, including ringforts, the circular enclosed farmsteads that were the standard unit of rural settlement at the time, many of which had souterrains built into or near their interiors. It is likely, though not confirmed for this site, that a similar association once existed here. The townland name Lissodeige itself may contain the Irish element lios, meaning a ringfort or enclosure, which would be consistent with that pattern.