Indonesia is a presidential, constitutional republic with an elected legislature. It has 34 provinces, of which five have special status. The country's capital, Jakarta, is the world's second-most populous urban area. Indonesia shares land borders with Papua New Guinea, East Timor, and the eastern part of Malaysia, as well as a maritime border with Singapore, Vietnam, the Philippines, Australia, Palau, and India (Andaman and Nicobar Islands). Despite its large population and densely populated regions, Indonesia has vast areas of wilderness that support one of the world's highest levels of biodiversity.