Although Java covers only 6 percent of Indonesia's landmass, more than half the population of the country lives on this island. Java is also the country's economic and political center. Some of the biggest cities are here; Jakarta and Surabaya. But most of the island is farmland, rice fields, jungle and mountains with volcanic peaks. Most of the island's 100 million inhabitants live here, the majority being farmers. The Javanese is by far the main ethnic group in Indonesia. Other groups are the Sundanese and the Madurese.