Brazilian photographer Sebastião Salgado spent six years travelling around the Amazon region, capturing images of the forest, rivers and mountains for his latest book, Amazônia.
"For me, it is the last frontier, a mysterious universe of its own, where the immense power of nature can be felt as nowhere else on Earth," he says.
"Here is a forest stretching to infinity that contains one tenth of all living plant and animal species, the world's largest single natural laboratory."
A lifelong advocate for the Amazon's indigenous people, Salgado documented the daily lives of a dozen of the tribes scattered throughout the rainforest - from hunting and fishing expeditions, to dances and rituals.
Born in 1944, Salgado left a career in economics to start as a photographer in 1973.
He worked on international assignments for a variety of photography agencies before forming his own, Amazonas Images, with his wife, Lélia, in 1994.
Over the years, Salgado's work has featured in numerous exhibitions and books, the latest of which brings together his Amazon photography.
"My wish, with all my heart, with all my energy, with all the passion I possess, is that in 50 years' time this book will not resemble a record of a lost world," he says.
"Amazônia must live on."
Amazônia, by Sebastião Salgado, is published by Taschen.