The Territory of Christmas Island is an Australian external territory in the Indian Ocean comprising the island of the same name. It is located approximately 350 kilometres south of Java and Sumatra and about 1,550 km (840 nmi) north-west of the closest point on the Australian mainland. It has an area of 135 square kilometres (52 sq mi).

Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's most populous island, home to approximately 56% of the Indonesian population. Indonesia's capital city, Jakarta, is on Java's northwestern coast.