The book "A Narrative of Travels on the Amazon and Rio Negro, with a Description of the Native Tribes and Observations on the Climate, Geology and Nature of the Amazon Valley" was written by the eminent naturalist and ethnographer Alfred Russell Wallace. In this book, the author describes in detail his adventures and research during his travels through the underground river of South America. He talks about encounters with different indigenous tribes, their customs and culture, and also shares his observations about the extraordinary biodiversity and unusual climate of the Amazon Valley. The book is a valuable source of information for those interested in the nature, ethnography and history of this unique region.