Mount Tambora, or Tomboro, is an active stratovolcano in West Nusa Tenggara, Indonesia. Located on Sumbawa in the Lesser Sunda Islands, it was formed by the active subduction zones beneath it. Before 1815, its elevation reached more than 4,300 metres high, making it one of the tallest peaks in the Indonesian archipelago. Tambora violently erupted in a series of eruptions beginning 5 April 1815, culminating in the largest eruption in recorded human history and the largest of the Holocene.