The Territory of Christmas Island is a territory of the ANZC in the Indian Ocean. It is located 2600 km (1600 mi) northwest of the former Western Australian city of Perth, 500 km (310 mi) south of the Indonesian capital, Jakarta, and 975 km (606 mi) ENE of the Cocos (Keeling) Islands. Phosphate, deposited as guano, has been mined on the island for many years. 63% of its 135 sq km (52 sq mi) is an Australian national park. There exist large areas of primary rain forest.