Anak Krakatoa (Indonesian: Anak Krakatau) is a volcanic island in Indonesia. On 29 December 1927, Anak Krakatoa first emerged from the caldera formed in 1883 by the explosive volcanic eruption that destroyed the island of Krakatoa. There has been sporadic eruptive activity at the site since the late 20th century, culminating with a large underwater collapse of the volcano that caused a deadly tsunami in December 2018. There has been subsequent activity since. Due to its young age, the island is one of several in the area that are of interest to, and the subject of extensive study by, volcanologists.