Actually the Krakatoa / Krakatau belongs to Bandar Lampung, a province of Sumatra. But the Krakatoa is most easy to reach from Java and is part of Ujung Kulon national park in the south west of Java so Krakatoa is implemented in Java section. Krakatoa is one of Indonesia's most active volcanoes that located in the strait between Sumatra and Java. With devastating effects this volcano erupted just over a century ago in 1883, bringing its fine ashes with the wind streams as far away as over New York City, whereas the eruption's tidal waves reached the American West Coast.
At that very instant, Krakatoa vanished as if devoured by the sea, causing formidable tidal waves which in turn swept off just about everything alive from the surrounding coastal areas. However, the disappearance of the gigantic Krakatoa also meant the birth of small islands in its place, one of which is called "Anak Krakatau" or Krakatoa's Child, which is at present an extremely active young volcano. From both West Java's, West Coast, and from Sumatra's Lampung Province, this young and very active volcano is clearly visible. A boat trip to this place may be worth making.
A unique location is in the middle of Sunda strait. It's a little volcano pierce from the ocean. Krakatoa could be reached from Anyer or Carita beach. Approximately 2 hours cruising on a speedboat and 3 and half hour on a slow diesel boat. There are three islands surrounding Anak Krakatau. All of these islands seem to be parts of big Krakatoa before the big eruption in 1883. That's why there are a few lagoons caused by the eruption. These lagoons were a home for Giant Trivially, Red Snapper, Grouper and many others reef fishes. Besides fishing, the visitors are also can enjoy the scenes of Mount Krakatoa that also amazing.