Siberut is one of the Mentawai Islands, lying west of Sumatra in the Indian Ocean. The most important home for the Mentawai people, it is a national park covered with rainforest but subject to some logging.
The island is known for its range of primates, including the Kloss Gibbon, Langur, Mentawai Langur and Mentawai Macaque .
Siberut was devastated by the 2004 Indian Ocean earthquake tsunami, but without any known loss of human life. One report stated that the island may have been raised up to two metres by the earthquake.