Summary of site:

# 384. The Mullyard stream sinks at the base of a rock wall as the stream bed crosses the boundary between the Meenymore Formation above on to the Dartry Limestone. A convoluted entrance gives access to a traverse above a pit, followed by a muddy crawl into standing water up to the roof, the first of a series of ducks. Exploration terminates at a sump which has been dived for 3m; the passage continues thereafter.

Mullyard Sink is thought to resurge at Mullyard Rising, about 1km to the south in the valley.