Mount Yasur is an active volcano on Tanna Island, Vanuatu, 361 m (1,184 ft) high above sea level, on the coast near Sulphur Bay, southeast of the taller Mount Tukosmera, which was active in the Pleistocene. It has a largely unvegetated pyroclastic cone with a nearly circular summit crater 400 m in diameter. It is a stratovolcano, caused by the eastward-moving Indo-Australian Plate being subducted under the westward-moving Pacific Plate. It has been erupting nearly continuously for over 800 years, although it can usually be approached safely.