Besides having vigorous volcanic activities, Java is also the most densely inhabited island in Indonesia. Krakatoa is located towards the west of Java and it has a lot of good diving spots. Divers can also explore the thriving marine and coral life of the hundreds of islands located offshore. Penietan Island and the peninsula are part of the national park of Ujung Kulon and it boasts some of the most spectacular animals of Javanese rainforest and surfing beaches. Divers can enjoy a diverse marine life in this diving spot as well as Pulau Seribu, which are tiny islands renowned as weekend destinations to visitors from Jakarta.