Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian and Pacific oceans. Comprising between 13,000 and 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea, it is the world's largest archipelagic state and the 14th-largest country by area. Indonesia has extensive tropical forests and marine ecosystems that support one of the world's highest levels of biodiversity.