Sumatra (Indonesian: Sumatera) is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are shared between Indonesia and other countries) and the sixth largest island in the world at 473,481 km with a population of 50,365,538. Its biggest city is Medan with a population of 2,109,330.
Sumatra forms an elongated landmass spanned diagonal northwest — southeast axis. The Indian Ocean borders the west, northwest and southwest sides of Sumatra with the island chain of Simeulue, Nias and Mentawai bordering along the southwestern coast. On the northeast side the narrow Strait of Malacca separates the island from Malay Peninsula, an extension of Eurasian continent. On the southeast the narrow Sunda Strait separates Sumatra from Java. The northern tip of Sumatra borders the Andaman islands, while on the lower eastern side are the islands of Bangka and Belitung, Karimata Strait and the Java Sea. The Bukit Barisan mountains, which contain several active volcanoes, forms the backbone of the island, while the northeast sides are outlying lowlands with swamps, mangrove and complex river systems. The equator crosses the island at its center on West Sumatra and Riau provinces. The climate of the island is tropical, hot and humid with lush tropical rain forest originally dominating the landscape.
Settler colonies began arriving in Sumatra around 500 BC, and several significant kingdoms flourished there. I Ching, a Chinese Buddhist monk, studied Sanskrit and spent four years of his life working in Palembang. The explorer Marco Polo visited Sumatra in 1292.
Sumatra has a huge range of plant and animal species but has lost almost 50% of its tropical rainforest in the last 35 years, and many species are Critically Endangered such as Sumatran Tiger, Sumatran Rhino and Sumatran Orangutan.
87% of Sumatrans are thought to be Muslim. The island is home to 22% of