The whole structure is tight enough to give a modern visitor pause: the entrance is just half a metre wide, and the passage itself rises to only 0.85 metres in height, meaning anyone entering would have had to crawl. That the inner reaches are now inaccessible makes the full extent of the system genuinely unknown.

The souterrain sits within a rath, the Irish term for a roughly circular earthen enclosure, typically dating from the early medieval period and associated with farmsteads of the fifth to twelfth centuries. Souterrains, underground passages and chambers built using corbelling and lintels, were a common feature of such settlements across Ireland, and were used variously for storage, refuge, or both. This particular example enters through a lintelled opening in the south-eastern half of the rath, runs briefly to the south-east before turning sharply to the west-south-west, and then passes through a slumped circular aperture into a corbelled passage roughly three metres long. The stonework includes roughly hewn limestone lintels, corbelling being a technique in which stones are layered so that each course projects slightly inward to form a self-supporting roof or wall. This leads finally to an oval chamber measuring approximately 1.4 by 1.2 metres, beyond which the passage appears to carry on, though how far remains unclear.