Java is one of the Greater Sunda Islands in the South East Asian country of Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 158.08 million people (including Madura) in mid 2025, projected to have risen to 159.2 million by mid 2026, Java is the world's most populous island, home to approximately 56% of the Indo Java is one of the Greater Sunda Islands in the South East Asian country of Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 158.08 million people (including Madura) in mid 2025, projected to have risen to 159.2 million by mid 2026, Java is the world's most populous island, home to approximately 56% of the Indonesian population while constituting only 7% of its land area. Indonesia's capital city, Jakarta, is on Java's northwestern coast. Many of the best known events in Indonesian history took place on Java. It was the centre of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically, and culturally. Four of Indonesia's eight UNESCO world heritage sites are located in Java: Ujung Kulon National Park, Borobudur Temple, Prambanan Temple, and Sangiran Early Man Site. Java was formed by volcanic eruptions due to geologic subduction of the Australian Plate under the Sunda Plate. It is the 13th largest island in the world and the fifth largest in Indonesia by landmass, at about 132,644.29 square kilometres (51,214.25 mi2) (including Madura's 5,408.35 square kilometres (2,088.18 mi2) and smaller offshore islands). A chain of volcanic mountains is the east–west spine of the island. Four main languages are spoken on the island: Javanese, Sundanese, Madurese, and Betawi. Javanese and Sundanese are the Java is one of the Greater Sunda Islands in the South East Asian country of Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 158.08 million people (including Madura) in mid 2025, projected to have risen to 159.2 million by mid 2026, Java is the world's most populous island, home to approximately 56% of the Indonesian population while constituting only 7% of its land area. Indonesia's capital city, Jakarta, is on Java's northwestern coast. Many of the best known events in Indonesian history took place on Java. It was the centre of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically, and culturally. Four of Indonesia's eight UNESCO world heritage sites are located in Java: Ujung Kulon National Park, Borobudur Temple, Prambanan Temple, and Sangiran Early Man Site. Java was formed by volcanic eruptions due to geologic subduction of the Australian Plate under the Sunda Plate. It is the 13th largest island in the world and the fifth largest in Indonesia by landmass, at about 132,644.29 square kilometres (51,214.25 mi2) (including Madura's 5,408.35 square kilometres (2,088.18 mi2) and smaller offshore islands). A chain of volcanic mountains is the east–west spine of the island. Four main languages are spoken on the island: Javanese, Sundanese, Madurese, and Betawi. Javanese and Sundanese are the most spoken. The ethnic groups native to the island are the Javanese in the central and eastern parts and Sundanese in the western parts. The Madurese in the Eastern salient of Java are migrants from Madura Island (which is part of East Java Province in administrative terms), while the Betawi in the capital city of Jakarta are hybrids from various ethnic groups in Indonesia. Most residents are bilingual, speaking Indonesian (the official language of Indonesia) as their first or second language. While the majority of the people of Java are Muslim, Java's population comprises people of diverse religious beliefs, ethnicities, and cultures. Java is divided into four administrative provinces: Banten, West Java, Central Java, and East Java, and two special regions, Jakarta and Yogyakarta. The island's exceptional fertility and rainfall allowed the development of wet-field rice cultivation, which required sophisticated levels of cooperation between villages. Out of these village alliances, small kingdoms developed. The chain of volcanic mountains and associated highlands running the length of Java kept its interior regions and peoples separate and relatively isolated. Before the advent of Islamic states and European colonialism, the rivers provided the main means of communication, although Java's many rivers are mostly short. Only the Brantas river and Solo river could provide long-distance communication and this way their valleys supported the centers of major kingdoms. A system of roads, permanent bridges, and toll gates is thought to have been established in Java by at least the mid-17th century. Local powers could disrupt the routes as could the wet season and road use was highly dependent on constant maintenance. Consequently, communication between Java's population was difficult. Java is the most populous major island in the world and is home to 55% of Indonesia's population, with a combined population of 156.9 million according to the official estimates as at mid 2024 (including Madura's 4.16 million). At about 1,192 people per km2 in 2025, it is also one of the most densely populated parts of the world, on a par with Bangladesh. Every region of the island has numerous volcanoes, with the people left to share the remaining flatter land. Because of this, many coasts are heavily populated and cities ring around the valleys surrounding volcanic peaks. The