The strait between the Indonesian islands of Java and Sumatra that was the site of the 1883 Krakatoa eruption was the Sunda Strait.
The Sunda Strait is a roughly southwest-to-northeast waterway linking the Java Sea with the Indian Ocean. Krakatoa, more accurately spelled Krakatau, stood among volcanic islands in the strait. Its catastrophic eruption began in May 1883 and reached its climax on 27 August, when enormous explosions destroyed much of the island and caused deadly tsunamis along both coasts.
The eruption dramatically reshaped the area. Pyroclastic flows crossed the water on superheated steam, while waves reached about 42 metres along western Java and 24 metres along southern Sumatra. More than 36,000 deaths are commonly associated with the disaster, most caused by tsunamis.
A common mix-up is with the nearby Strait of Malacca, which separates Sumatra from the Malay Peninsula. The Sunda Strait instead separates Sumatra from Java. Anak Krakatau later emerged from the collapsed volcanic caldera in 1927.