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 comprising four islands. Two of them are known as Lang and Verlaten; another, Rakata, is the only remnant of an island mostly destroyed by an eruption in 1883 which created the caldera.
In 1927, a fourth island, Anak Krakatoa, or "Child of Krakatoa", emerged from the caldera formed in 1883. There has been new eruptive activity since the late 20th century, with a large collapse causing a deadly tsunami in December 2018.
Wikipedia https://en.wikipedia.org/wiki/Krakatoa
Coordinates -6°6'0.449" N 105°25'22.319" E