Krakatoa sits in the Sunda Strait between Java and Sumatra, and its name alone carries a weight few volcanoes can match. The catastrophic 1883 eruption destroyed most of the original island, generated tsunamis that killed over 36,000 people, and sent shockwaves around the globe. The sound of the blast was heard nearly 5,000 kilometres away in Australia.
What visitors see today is Anak Krakatau, the "Child of Krakatoa," which emerged from the caldera in 1927 and has been growing ever since. The young volcano remains active; a major eruption and partial collapse in December 2018 triggered another deadly tsunami along the coasts of Java and Sumatra. Access is sometimes restricted depending on volcanic activity, so check conditions before planning a trip.
Most tours depart from Carita or Anyer on the west coast of Java, crossing the strait by speedboat in roughly ninety minutes. The journey passes small fishing villages and, on a clear day, offers views of both Java and Sumatra. On the island itself you can walk across fields of black volcanic sand, see steam venting from cracks in the rock, and snorkel the coral reefs around neighbouring Rakata Island, the largest surviving remnant of the original Krakatoa.