How the Earth Was Made | The Most Dangerous Volcanoes

Krakatoa, also transcribed Krakatau, is a caldera in the Sunda Strait between the islands of Java and Sumatra in the Indonesian province of Lampung.

The caldera is part of a volcanic island group (Krakatoa archipelago) comprising four islands.

Two, Lang and Verlaten, are remnants of a previous volcanic edifice destroyed in eruptions long before the famous 1883 eruption; another, Rakata, is the remnant of a much larger island destroyed in the 1883 eruption.