An irregular hollow in the grass, roughly fifteen metres north to south and ten metres east to west, marks the roof of something built underground, long ago, and still largely intact beneath the surface. A broken lintel and a stretch of exposed drystone walling hint at the structure below, but the bulk of it remains hidden, accessible only through local knowledge and, apparently, three chambers waiting in the dark.

The feature sits within the western half of a rath, a type of circular earthwork enclosure that served as a farmstead during the early medieval period in Ireland, broadly between the fifth and twelfth centuries. Raths are common across the Irish landscape, but the souterrains associated with them are less immediately visible, which is partly the point. A souterrain is an underground stone-built passage or chamber, typically constructed using drystone walling and large flat roof lintels, just as the exposed fragment here suggests. Their precise function is still debated, but they are generally thought to have served as cool storage spaces, places of refuge, or both. The three-chamber arrangement reported at Carrownaraha is consistent with souterrains found elsewhere in Ireland, where multiple interconnected chambers were sometimes linked by low crawl-ways. That local memory has preserved knowledge of the internal layout, even though the structure is not formally excavated, suggests the site has not been entirely forgotten by those living nearby.