The original entrance to the souterrain, a type of underground stone-lined tunnel built during the early medieval period and associated with nearby settlement enclosures, was recorded as lying roughly two metres east of the ringfort's perimeter. That opening is now filled in, but the ground itself has begun to give the game away: a more recent collapse towards the centre of the interior has exposed a creephole, an earth-cut passage just wide enough to crawl through, running off in a south-westerly direction.

The souterrain was first noted by O'Shea and Crowley in 1972, working from fieldwork that would later feed into the published Archaeological Inventory of County Cork. Souterrains are found across Ireland, typically associated with ringforts, the circular earthwork enclosures that dot the Irish countryside from the early medieval period, broadly the fifth to twelfth centuries. Their precise function is still debated, though cold storage and refuge during raids are the most commonly cited possibilities. What makes the Loughane More example quietly compelling is precisely its current state: the deliberate entrance has vanished, yet the structure underneath is slowly announcing itself through subsidence, its roof giving way in a manner that makes the underground geography legible from above.