Siberut is the largest and northernmost of the Mentawai Islands, located 150 kilometres west of Sumatra in the Indian Ocean.

Siberut Island has a hot and humid tropical rainforest climate, with an annual rainfall of 4,000 mm (157.48 in).

The west coast features mainly Barringtonia forests and is difficult to get to because of rough seas and steep cliffs.

The hilly interior elevates to 384 metres (1,260 feet),[5] with many streams eventually forming rivers in the sago-grove lowlands and swamp forests.

In 2001, UNESCO brought in a new phase of its Siberut Programme, with the intention of protecting the ecosystem through local development.

[8] The Swiss anthropologist, Reimar Schefold spent years among the Siberut groups, the Sakuddei.