Pressing through its surface are stone lintels, the flat capstones that once roofed an underground passage running beneath the ground. The passage itself is blocked and cannot be entered, but those exposed stones are enough to confirm what lies beneath, a souterrain sealed against the world.

A souterrain is a man-made underground tunnel or chamber, typically associated with early medieval settlement in Ireland, roughly the sixth to twelfth centuries. They were constructed from stone, roofed with large flat lintels, and buried under the earth, serving variously as storage spaces, places of refuge, or both. This particular example sits in the south-east quadrant of a cashel, which is a stone-walled enclosure of the same period, essentially a fortified farmstead built from dry-stone masonry rather than earthen banks. The combination of cashel and souterrain is not unusual in early medieval archaeology, but finding the two together at Meenymore, in a part of Leitrim that tends not to draw much attention, gives the site a quiet weight. The mound above the souterrain has settled over centuries into something that might easily be dismissed as a natural rise in the ground.