February - 2017

Mulu’s Caves are legendary. They boast the world’s 2nd largest cave chamber, the largest cave in the world by volume and one of the largest cave passages in the world. These are undoubtedly one of the greatest series of caves on the planet.

In 1978 the discovery of Clearwater Cave in Gunung Api set the ball rolling and put Mulu on the world stage. This cave formed the main resurgence for the mountain and during the first expedition to the area it revealed 26km of previously unknown passages, most of which were massive by world standards. In the same mountain Cave of the Winds and Solo were discovered on the western flank of Api whilst on the eastern side Wonder and Prediction Caves were found within the deep and remote Hidden Valley. This set the stage for a series of expeditons which would discover and link together many more caves to form the Clearwater Cave System in the west and the Caves of the Hidden Valley on the east.

During the 1978 expedition the Terikan River Caves were explored on the northern flanks of Gunung Benarat and although not linked during that expedition it was clear that these formed parts of the main reurgence for the mountain which would be a significant focus for further exploration. It was 28 years later, during the Benarat ‘05 expedition, that these caves were linked by diving the sumps to form the Terikan Caves System.

Exploration on the southern flank of Benarat during 1978 had revealed Benarat Caverns which has since been linked into Cobweb Cave through Moon Cave to form the Benarat Caverns System.

Over the past 30 years further explorations in both mountains have discovered, explored and subsequently connected many significant caves to form the four major systems:

The Park contains three main limestone blocks. Gunung Api, Gunung Benarat and the Southern Hills. Each of these contain caves of significant dimensions. In the Southern Hills the Major caves are Deer and Green Caves. In Gunung Api BLackrock Cave was discovered in 1988. This proved to be a significant component of the Clearwater System but exploration only revealed low lying passages. It was clear that something must lie above this cave but it was not until 2003 that a small entrance was discovered 2km  south of the Melinau Gorge. This was Whiterock Cave which provided a feast of exploration for five expeditions with 80km of passages explored to date; now the longest individually named cave in the Park.

The first Mulu expedition produced a comprehensive list of its discoveries which has been maintained and updated over the past 33 years of exploration to form the All Mulu Chart. This provides a record of every named cave in the Park.

To date over 362km (2011) of caves passages have been surveyed and mapped in the limestone mountains of the Gunung Mulu National Park. The exploration continues.