When explorers discovered Cobra Cave in 1984, little did they know that they had stumbled on the lower end of Mulu’s deepest cave sytem. It would be a further fourteen years until this became a reality.
Total Length: 20,632.27m
Vertical Range: 489.40m
Cobra Cave situated 200m downstream of Nasib Bagus forms the resurgence for the lowest sink in the Hidden Valley. Early exploration revealed a strike controlled cave which heads into the mountain for 1.5km. Not far from the entrance a stalagmite column which resembles a Cobra snake stands guard in the centre of the passage and gives the cave its name.
During the 1996 Hidden Valley expedition the discovery of Bridge and Cloud Caves in the deep dolines between the Hidden Valley Gorge and Nasib Bagus provided a feast of exploration. Although a connection between these two caves was not proven that year the 100m deep connecting shaft, The Abyss, was found. Towards the end of the expedition a steep bouldery ramp in Cloud Cave was followed downwards for 350m to a streamway in a canyon passage. Further investigation revealed an eyehole high above which provided the link into Cobra Cave. The system was now 270m deep and 5.6km in length.
The 1998 Hidden Valley expediton was based outside Nasib Bagus and access to the caves was via the newly discovered connection through Cobra Cave. Further discoveries were made in the high levels of Bridge Cave. A bag which was dropped down The Abyss was subsequently found lying in Kamakazi Highway in Cloud Cave, so the connection was confimed. Following the expedition a group of Park guides returned to Bridge Cave to descend another pitch which dropped into Cloud Cave thus proving the connection between the caves. This established the length of the system at 15.6km with a depth of 460m, the greatest vertical range of any cave in the Park.