Mulu
Located inland, close the border with Brunei, Gunung Mulu National Park is a UNESCO World Heritage Site and home to some of the most diverse and dramatic scenery in Borneo. With incredible cave systems, tree-top canopy walkways, winding jungle paths and towering limestone pinnacles, there is plenty to explore.
At 544 square kilometers, Mulu is Borneo’s largest national park. The superlatives continue as Mulu is also home to the largest natural chamber in the world; the Sarawak Chamber and the longest cave passage in the world; the Deer Cave, which is over two kilometers long. Within many of the caves live large bat colonies, and watching them spiral out into the dusk is often one of the highlights of a trip to Mulu.