14. Gunung Mulu National Park
Famous for its extraordinary limestone karst formations and phenomenal cave systems, the Gunung Mulu National Park is one of the most awe-inspiring natural attractions in all of Southeast Asia. Located in Malaysian Borneo in the Sarawak State, this national park features some of the largest and longest cave systems in the world. Included in these is the world’s largest cave chamber, the Sarawak Chamber, which is estimated large enough to hold 40 Boeing 747 aircraft.