Java is an island of Indonesia. At about 138,800 square kilometres (53,600 sq mi), the island is comparable in size to England, the U.S. State of North Carolina, Chinese Province of Anhui or Omsk Oblast. With a population of over 141 million or 145 million, Java is home to 56.7 percent of the Indonesian population and is the world's most populous island. The Indonesian capital city, Jakarta, is located on western Java. Much of Indonesian history took place on Java. It was the center of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically and culturally. Four of Indonesia's eight UNESCO world heritage sites are located in Java: 1) Ujung Kulon National Park, 2) Borobudur Temple, 3) Prambanan Temple, and 4) Sangiran Early Man Site.