The souterrain recorded at Finnure in County Sligo belongs firmly to the second category. A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval settlement in Ireland, often used for storage or refuge. At Finnure, even that much is uncertain. When the site was physically inspected in 2003, no visible remains could be found at ground level whatsoever.

The monument is linked to the Finnure rath, a rath being a circular earthen enclosure that typically surrounded an early medieval farmstead. A second souterrain was also recorded nearby, suggesting that at some point the site may have held genuine archaeological significance. Neither feature appeared in the 1989 Survey of Monuments and Places, though both were eventually included in the Record of Monuments and Places compiled in 1995. That gap between the two surveys hints at the difficulty of cataloguing a landscape where features can be intermittent, ambiguous, or simply very easy to miss. By the time anyone looked closely enough to confirm what was actually there, the ground had apparently given nothing away.