Built typically from the eighth to the twelfth centuries, souterrains were dug into the earth and lined with drystone walling, often roofed with large flat slabs. Their precise function is still debated: some served as cool storage for foodstuffs, others appear to have been refuges, and many are found within or immediately adjacent to ringforts, suggesting they were integral to the defensive and domestic life of a farmstead.

The placename Lisnageeragh is itself suggestive. The first element, lios, refers to a ringfort, the circular earthen enclosure that was the standard unit of rural settlement in early medieval Ireland, and the presence of a souterrain here fits a pattern seen across the country, where such underground features were constructed as ancillary to exactly that kind of enclosed settlement. Beyond the fact of its existence and its location, the specific details of this particular souterrain, its dimensions, its construction, the date of its recording, any finds associated with it, remain undocumented in publicly available sources at present.