Java and Bali to the east. Borneo lies to the north and Christmas Island is to the south. It is the world's 13th largest island. Java is surrounded by the Java Sea to the north, Sunda Strait to the west, the Indian Ocean to the south and Bali Strait and Madura Strait in the east. Java is almost entirely of volcanic origin; it contains thirty-eight mountains forming an east–west spine that have at one time or another been active volcanoes. The highest volcano in Java is Mount Semeru (). The most active volcano in Java and also in Indonesia is Mount
Second Battle of the Java Sea discovered that the wrecks of HMS "Exeter" and HMS "Encounter" were missing from the ocean floor. The Guardian newspaper subsequently reported that the wrecks of HMS "Exeter", HMS "Encounter", and part of HMS "Electra", as well as the submarine USS "Perch" were missing and presumed illegally scavenged. Commenting on their removal, one of the men involved in their original discovery is stunned at the magnitude of the salvaging that appears to have taken place. Second Battle of the Java Sea The Second Battle of the Java Sea was the last naval action of the Netherlands East Indies campaign, of 1941–42.