Indonesia

Indonesia is a country made of islands.

There are thousands and thousands of them. Warm seas lie all around. Many islands have tall volcanoes and thick green forests. The capital city is Jakarta.

Indonesia is a country in Southeast Asia made of about 17,500 islands, and more than 7,000 of them have no people living on them. The islands lie between the Indian Ocean and the Pacific Ocean, and the Equator runs right across the country.

The biggest islands have forested volcanic mountains in the middle and flat land near the coast. The capital, Jakarta, is on the island of Java. About 286 million people lived in Indonesia in 2025, more than in any other country in Southeast Asia.

Indonesia lies off the coast of mainland Southeast Asia, between the Indian and Pacific oceans. Britannica describes an archipelago of some 17,500 islands, more than 7,000 of them uninhabited, that crosses the Equator and spans a distance equal to one-eighth of Earth's circumference: about 5,100 km from east to west and 1,800 km from north to south.

The islands fall into groups: the Greater Sunda Islands (Sumatra, Java, southern Borneo, called Kalimantan, and Sulawesi), the Lesser Sunda Islands from Bali eastward through Timor, the Moluccas, and the western part of New Guinea. Almost three-fourths of the land is in Sumatra, Kalimantan and western New Guinea. The World Bank put the population at 285,721,236 in 2025, making Indonesia the most populous country in Southeast Asia; its capital, Jakarta, lies near the northwestern coast of Java.

Jakarta is the biggest city in Indonesia.

It is on the island of Java. In the middle of Java stands Borobudur. It is a huge old stone temple. It is shaped like a hill with steps.

Jakarta, the capital and largest city, lies on the northwest coast of Java where a river meets the Java Sea. It is a center for trade and money. Surabaya, also on Java, is the second-largest city and a big port.

In central Java, Borobudur is a Buddhist temple from the 700s and 800s. It rises in tiers, with square terraces at the bottom, round platforms above and 72 small stupas, each holding a statue of the Buddha. Not far away, the Prambanan temples, from the 800s, are carved with scenes from the old Ramayana story. Both became World Heritage Sites in 1991.

Jakarta, at the mouth of the Ciliwung River on Jakarta Bay, became a special capital district in 1966; the district counted 10,562,088 people in 2020 (Britannica). Four of Indonesia's five largest cities, Jakarta, Surabaya, Bandung and Bekasi, are on Java; the fifth, Medan, is on Sumatra. Yogyakarta, capital of the revolutionary government from 1946 to 1949, is a center of batik making and the arts.

UNESCO describes Borobudur, built in the 8th and 9th centuries under the Syailendra dynasty, as a stupa in three tiers around a hill: a pyramidal base with five square terraces, three circular platforms with 72 openwork stupas, and a monumental stupa on top, with 2,520 m² of relief carving. It was abandoned sometime between the 10th and 15th centuries, rediscovered in the 19th and restored with UNESCO's help in the 1970s. The Prambanan compounds, with more than 500 temples, include 9th-century Hindu temples whose reliefs illustrate the Indonesian version of the Ramayana; both sites were inscribed in 1991.

Indonesia has lots of volcanoes.

Some of them still puff out smoke and ash. It is warm all year. It rains a lot, and big green forests grow. Only the highest mountains get snow.

Indonesia has more than 100 active volcanoes, in a long curved line through Sumatra and Java and on to other islands. Ash from volcanoes makes some of the soil very rich for farming. In 1883 the volcano Krakatoa, between Sumatra and Java, erupted so strongly that ash circled the Earth and made colorful sunsets for more than a year.

Because Indonesia sits on the Equator, it is warm all year, and most places get heavy rain, especially from December to March. Only the Maoke Mountains in Papua are high enough for snow. Their tallest peak, Jaya Peak, is 4,884 meters high, the highest point in Indonesia.

Indonesia sits where three major sections of Earth's crust meet: the Sunda Shelf, an extension of Asia carrying Borneo, Sumatra, Java and Bali; the Sahul Shelf, an extension of Australia carrying New Guinea; and a belt of mountains running south from Japan and the Philippines. Deep trenches bound the island arc, such as the Java Trench, about 7,450 m deep. More than 100 volcanoes are active, in a crescent along the outer margin of the country; Java alone has some 50 active cones. Krakatoa's 1883 eruption sent ash clouds around the Earth, and Mount Sinabung in northern Sumatra erupted in 2010 after more than 400 years.

Temperatures depend on elevation rather than latitude: coastal means range from the low 20s to low 30s °C, and only the Maoke Mountains, with Jaya Peak at 4,884 m, receive snow. Monsoon winds bring heavy rain from December to March; from central Java eastward the dry season (June to October) grows longer toward Australia. Lake Toba in northern Sumatra covers about 1,140 km² at some 900 m above sea level.

The Komodo dragon is a giant lizard.

It lives on a few small islands. Orangutans live on the big islands of Borneo and Sumatra. Proboscis monkeys live on Borneo. The shallow seas have coral reefs.

Indonesia lies between two great groups of animals. In the west live Asian animals such as orangutans, tigers, rhinoceroses and elephants. In the east live animals related to Australia's, such as cockatoos, birds of paradise and pouched mammals called cuscuses.

The Komodo dragon, the largest living lizard, lives only on a few islands, mostly in Komodo National Park. Orangutans live on Borneo and Sumatra, and the proboscis monkey lives on Borneo. Indonesia also has about 40,000 kinds of flowering plants, including Rafflesia arnoldii, the world's largest flower.

Wallace's Line, running between Borneo and Sulawesi and between Bali and Lombok, marks the boundary between the Oriental fauna of Asia to the west (rhinoceroses, orangutans, tapirs, tigers, elephants) and the Australian fauna to the east (cockatoos, bowerbirds, birds of paradise, bandicoots, cuscuses). Many islands have endemic species, among them the babirusa of Sulawesi.

The Komodo dragon (Varanus komodoensis), the largest living lizard, averages 2 to 3 m; UNESCO estimates about 5,700 on Komodo, Rinca, Gili Motong and coasts of western and northern Flores. The Tropical Rainforest Heritage of Sumatra (2004), three national parks covering 2,595,124 ha, holds an estimated 10,000 plant species, 201 mammal species including the endemic Sumatran orangutan, the Sumatran tiger, rhino and elephant, and some 580 bird species; UNESCO notes that Sumatra's forest has been reduced to isolated remnants in only 50 years. Most remaining Javan rhinoceroses live in Ujung Kulon National Park on Java's western tip.

Many different groups of people live in Indonesia.

They speak hundreds of languages. Indonesian is the language they share. Many families grow rice in wet green fields. Batik cloth is made with wax and dye.

Indonesia has more than 300 ethnic groups and more than twice as many languages. Its motto, Bhinneka tunggal ika, means Unity in diversity. Indonesian, which grew from Malay, is the national language, and people also speak Javanese, Sundanese, Madurese and many more.

Nearly nine out of ten people follow Islam, and there are also Christians, Hindus, Buddhists and others; Hinduism is the main religion on Bali. In Java many villages are surrounded by rice paddies, some climbing the hills in terraces. Batik, cloth decorated by drawing on it with hot wax before dyeing, is worn at work, in schools and universities, and at celebrations such as weddings.

Britannica counts more than 300 ethnic groups and more than twice as many languages. The Javanese, about one-third of the population, are the largest group, followed by the Sundanese and Madurese. Most Indonesians speak Austronesian languages; Papuan languages are spoken in western New Guinea and parts of the Moluccas, and Indonesian (Bahasa Indonesia), which evolved from Malay, is the unifying national language. The Minangkabau of western Sumatra trace inheritance and descent through the female line.

Nearly nine-tenths of Indonesians profess Islam; Hindus are under 2 percent nationally but the majority on Bali, and there are Christian communities in Flores, Timor, northern Sulawesi, inland Kalimantan and the Moluccas. In Bali, UNESCO's 2012 listing describes subak, a cooperative system of canals and weirs dating to the 9th century, with about 1,200 water collectives sharing water among rice farmers. UNESCO added Indonesian batik (2009) and gamelan, the percussion orchestra of forged-metal gongs and xylophones played by people of all ages (2021), to its Intangible Cultural Heritage lists.