Ujung Kulon National Park is a national park at the westernmost tip of Java, located in Sumur District of Pandeglang Regency, part of Banten province in Indonesia. It once included the volcanic island group of Krakatoa in Lampung province, although current maps has suggested the Krakatoa island group as its own protected area, the Pulau Anak Krakatau Marine Nature Reserve.

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.