Running parallel to the Great Hall and interconnected to it via several passages is Flintstone Passage. This splits into many different passages that break into the left bank of the canyon downstream of Holuca. Away from the river, Flintstone runs into another of the caves' unique passages, Mudwall Passage, which has filled with mud almost to the 3 m high roof. Following the infilling process a vadose trench has been cut the length of the passage revealing that the mud is formed of thin laminations.