Dozens of tribes around the world have managed to survive outside of the modern world, though their existence is perpetually at risk.

British photographer Jimmy Nelson tried to record them as they exist today, traveling to thirty one tribes from 2009 to 2012.

“My dream had always been to preserve our world’s tribes through my photography,” Nelson told Business Insider. "Their lifestyle is one of much more purity and beauty than ‘ours.’ It is free of corruption and greed. I want the tribes to be proud of their authenticity and defend it in order to preserve it.”

Nelson shared photos of some tribes, from the Tsaatan people of northern Mongolia to the Maasai people of Kenya. For the rest, check out his Web site and his book, "Before They Pass Away."