Krakatoa archipelago

The Krakatoa archipelago is a group of volcanic islands in the Sunda Strait between the islands of Java and Sumatra in Indonesia, notable for the catastrophic 1883 eruption. The archipelago includes several volcanic remnants and new cones that have formed since the 19th century.

The best-known feature is Anak Krakatau, a volcanic cone that first emerged above sea level in 1927 and has been repeatedly active since; it is closely monitored for explosive activity, collapse and tsunami risk. Boat trips from nearby ports provide views from the sea when authorities permit, but landing and close approaches are often restricted.

The archipelago’s history is dominated by the 1883 eruption that destroyed much of the original island complex and generated regional tsunamis; subsequent decades saw regrowth of volcanic cones and the long-term emergence of Anak Krakatau. More recent episodes of activity, including a major partial flank collapse in 2018, underline the continuing geological hazards and the need for monitoring.

• 1883 eruption: The 1883 eruption of Krakatoa is one of the largest volcanic explosions in recorded history and produced tsunamis that caused tens of thousands of deaths across the Sunda Strait.
• Visitor access: Periodic activity and hazard zones mean visitor access is restricted; boat trips operate from Java and Sumatra but are subject to advisories from Indonesian authorities.

What to See#

• Anak Krakatau: The volcanically active cone that emerged in 1927 and has grown in successive eruptions; notable for repeated eruptive activity and the 2018 partial flank collapse which generated a tsunami.
• Rakata: A remnant of the original 1883 island, forming a steep-sided volcanic mass that was largely left after the 1883 cataclysm and now forms part of the surviving archipelago.

Most trips to see the Krakatoa archipelago depart from the south coast of Lampung (e.g., Kalianda) or from Carita and Merak on western Java. Boat crossings to the islands typically take 2-4 hours depending on departure and sea conditions. For scientific updates and eruption advisories, consult the Indonesian Geophysical Agency (PVMBG) and the Smithsonian Global Volcanism Program.

• If visiting by boat, book a licensed operator from any of the Lampung harbors (e.g., Kalianda); rough seas are common-choose early-morning crossings when winds are calmer.
• Observe weather and volcanic advisories-child eruptions, ash, and gas emissions can close access at short notice.
• Visit the observation points on Anak Krakatau's flanks only with official guides; winding trails and fresh pumice are unstable.