The West Papua region in Indonesia is estimated to host more than 40 uncontacted groups. Verifying that number is difficult, however, because of the mountainous terrain and because journalists and human-rights organizations are banned from the region by the Indonesian government.
Others live in the Andaman Islands archipelago, between India and the Malay Peninsula.
Until recently, the Jarawa of the Andaman Islands avoided contact with outsiders, although the Great Andaman Trunk Road has brought both tourists and poachers, leading to disease outbreaks and exploitation of the tribe.
And just off the coast of the Andaman Islands is North Sentinel Island, home to the Sentinelese: A group that attacks just about anyone who comes ashore.
Source: Tech Insider
But most of the known uncontacted tribes live in South America, deep in the Amazon rainforest.
Brazil claims to have most of the world's uncontacted people, estimating as many as 77 tribes — though National Geographic estimates as many as 84. Many of them live in the western states of Mato Grosso, Rondonia, and Acre.
Illegal logging in the Amazon poses a huge risk for the indigenous people living in the region, and some uncontacted tribes have even come out of their isolation in protest of encroaching devastation.