If you stretched Indonesia out, end to end, it would be wider than the entire United States of America. From the western tip of Sumatra to the eastern edge of Papua is about 5,000 kilometres. That is why the country has three different time zones - when children in Jakarta are eating lunch, children in Papua are already finishing school.
The five biggest islands have names you can learn in one minute: Sumatra, Java, Borneo (shared with two other countries), Sulawesi, and Papua (also shared). Most people in Indonesia live on Java, which is only the fifth-biggest island but is the most crowded - around 150 million people, more than live in the whole of Russia.
Living on so many islands means lots of boats. Children in some villages take a wooden boat to school instead of a bus. Ferries the size of buildings carry cars, trucks and families between the bigger islands. From the air, the sea around Indonesia is dotted with little wooden boats heading in every direction.
Because the islands are spread out so far, each one has its own foods, dances, languages and animals. A tiger lives on Sumatra. An orangutan lives on Borneo. A bird-of-paradise lives on Papua. None of them swims across to visit the others. The sea between the islands has kept their wildlife wonderfully different.