Sumatra

The westernmost of Indonesia's great islands is a land of fire and water, of tigers and tropical forest. Sumatra is the sixth-largest island on Earth, a long volcanic ridge running northwest to southeast astride the equator, its mountains lined with active volcanoes and its lowlands once carpeted by some of the richest rainforest in Asia. Here roam the last Sumatran tigers, rhinos and orangutans, and here too lie the epicentres of some of the most violent earthquakes and tsunamis in modern history.

Sumatra covers about 473,481 square kilometres and is dominated by the Barisan Mountains, a volcanic spine that includes its highest point, the active volcano Mount Kerinci at 3,805 metres. The island sits squarely on the Sunda megathrust, where the Indo-Australian plate dives beneath Eurasia, a fault that ruptured catastrophically in December 2004 to generate the Indian Ocean tsunami. Cradled in its highlands is Lake Toba, the vast caldera of a supervolcano whose eruption some 74,000 years ago was among the largest in the past two million years. Equatorial rainforest, peat swamps and rivers fill the broad eastern lowlands.

Sumatra has long been a crossroads of trade, its ports drawing merchants seeking pepper, gold and camphor, and its sultanate of Aceh standing as a powerful Islamic state for centuries. The 2004 tsunami devastated Aceh, killing well over 100,000 people on the island alone and reshaping its northern coast. Today Sumatra remains an economic powerhouse for Indonesia, rich in oil, coal, palm oil and rubber, even as that wealth comes at the cost of one of the world's fastest rates of deforestation, pushing its iconic wildlife toward the brink.

• 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
• Java
  The world's most populous island, the crowded core of Indonesia neighbouring island