Christmas Island (Australia), island dependency of Australia, in the Indian Ocean, south of the western tip of Java. The island is mainly a plateau about 300 m (about 1000 ft) above sea level. The chief industry is the mining of phosphate rock. However, as the phosphate reserves begin to dwindle, the government is encouraging the development of tourism. The population is made up of Chinese, Malays, and a lesser number of Europeans. The island was annexed by Britain in 1888 and was incorporated in the Straits Settlements colony the following year. In 1900 it was made part of the Settlement of Singapore. During World War II (1939-1945), the island was occupied by the Japanese. It was transferred to Australian administration in 1958. Area, 135 sq km (52 sq mi); population (1993) 2,500.