libutron: The Pinnacles, Mulu National Park, Borneo, Malaysia | ©Manuel Beers Gunung Mulu National Park, on the island of Borneo, is the most studied tropical karst area in the world. The park is important both for its high biodiversity and for its karst features. It is dominated by Gunung Mulu, a 2,377 m-high sandstone pinnacle, and at least 295 km of explored caves provide a spectacular sight and are home to millions of cave swiftlets and bats. Since 2000 Gunung Mulu National Park is listed as