In Sarawak, Malaysia’s Mulu National Park, everything’s extra-sized. The short flight from Miri to Mulu is about the only thing brief about it—park visitors enter a 52,800-hectare karst limestone landscape covered in over 3,500 plant species, with some of the world’s most massive caves beneath.
Eons of erosion have carved out some 300km of caves from the limestone, including the Sarawak Chamber, the world’s largest natural chamber, and the 215km Clearwater Cave system, the most extensive interconnected cave system in the world. Cave swiftlets and wrinkle-lipped free-tailed bats occupy these depths in the millions.
Above ground, Gunung Mulu rises some 2,370m above the jungle, the highlight of a surprisingly varied terrain that includes rivers, floodplains, and needles of limestone called “pinnacles” jutting out of the forest.
Trekking and caving in Mulu require guides to see guests through safely; visitors planning to explore Mulu’s caves must book at least 3-4 weeks in advance.