December - 2018

Discovered: 1996

Length: 2,209.90m

Vertical Range: 220.13m

Connections: Bridge Cave, Cobra Cave

Part of: The Cobra/Cloud/Bridge Caves System

The entrance to Cloud Cave lies near the base of the fourth depression and is so large that clouds form in the entrance. The main passage is huge, being 80m high and 45m wide heading northwards towards the Hidden Valley to end in a total choke after a kilometre. Interestingly this choke is 100m below the level of the present day alluvial sinks in Hidden Valley, leading us to wonder if this was the original conduit of the Hidden Valley water or does it predate the valley and pass under it towards the summit of Gunung Api?

At the base of the enormous boulder ramp is a tall stream passage and an obscure duck under a hole in the wall provides a connection through to Cobra Cave which was explored from a camp in the Melinau Paku valley in 1984. The early explorers turned back at the end of Cobra, thinking that the passages were closing down, a few more metres and they would have found their way into the Cloud System twelve years earlier!

Bridge Cave is connected to Cloud Cave in two places, both down deep pitches. One of them, a huge 30m diameter, 95m deep shaft, The Abyss, has never been descended despite two attempts, although markers dropped down it were found at the base of a huge aven in Cloud Cave, proving the connection.

Cloud Cave 1998