Java

No island on Earth carries more people than Java. Though modest in size, this volcanic island holds more than 150 million inhabitants, well over half of Indonesia's population, packed at a density that rivals the most crowded countries in the world. It is the political, economic and cultural heart of the Indonesian archipelago, home to the sprawling capital Jakarta, ancient temple complexes and a chain of fertile volcanoes whose ash has fed rice paddies for thousands of years.

Java covers about 132,107 square kilometres, a long island running east to west south of Borneo and Sumatra. A spine of more than thirty volcanoes, many of them active, runs its length, including its highest peak, the restless Mount Semeru at 3,676 metres, and the notorious Merapi near the city of Yogyakarta. This volcanic geology is the secret of Java's extraordinary fertility: weathered ash produces some of the richest agricultural soil on the planet, supporting intensive rice cultivation that has sustained dense populations for millennia. The island sits on the same subduction zone that makes all of Indonesia so seismically active.

Java has been the seat of great civilisations, from the Buddhist kingdom that raised the colossal temple of Borobudur in the eighth century to the Hindu monuments of Prambanan and the later Islamic sultanates. Dutch colonial rule centred on the island, and it was here that Indonesian independence was proclaimed in 1945. Today Java's dominance is both its strength and its strain: Jakarta is sinking and choking on traffic and pollution, prompting Indonesia to begin relocating its capital to Borneo, even as Java remains the unrivalled centre of national life.

• Indonesia
  The world's largest archipelago, spanning two oceans located in
• Asia
  Earth's largest and most populous continent located on
• Krakatoa
  The Indonesian volcano whose 1883 eruption was heard across the world nearby volcano
• Sumatra
  A vast volcanic island anchoring western Indonesia neighbouring island