This pothole is formed along a single joint (a natural fracture, usually strongly directional, with no displacement) which exerts directional control. The entrance, in a small depression, leads to a first pitch initially inclined, then stepped, ending in a bedding plane. An upstream crawl ends in a chamber where water enters through the roof. Downstream leads to a second shaft, almost 30m deep, where the water vanishes into a narrow cleft in the floor. A 6m climb leads to the head of a 12m final pitch. Here the stream drains into an impenetrable crack. The long, deep shafts are all developed in the Knockmore Limestone Member of the Dartry Limestone.
The stream passing through Aughnakeeran is believed to join the drainage through Pollanaffrin.