10. Borneo
Population: 21,258,000
The largest island in Asia and the 3rd largest in the world, Borneo consists of 3 countries: Brunei, Malaysia and Indonesia. Before the end of the last Ice Age, Borneo was connected to mainland Asia, and with the islands of Java and Sumatra, formed the highlands of a peninsula. The island also has an extensive cave system, and the Borneo forest is one of the oldest at roughly 140 million years old.
