Mysteries of the Amazon:

This is new to me.
"...author David Grann discussed his journey deep into the jungle to trace the path of British explorer Percy Fawcett and his search for the mythical "Lost City of Z." Fawcett, who inspired Conan Doyle's The Lost World, embarked on his daring expedition in 1925, trying to find El Dorado, a so-called "lost city of gold" that was hidden in the Amazonian jungle. After sending out dispatches of his journey that were followed around the world for five months, he and his group vanished, Grann recounted.

While a number of missions over the years set out to find Fawcett, he and his party were never located. Some speculated that he'd found a mystical portal to another dimension and entered it. Working from Fawcett's diaries kept by his granddaughter, Grann went to the Amazon to follow Fawcett's route and learn what became of him. He spoke with indigenous tribespeople whose oral history included stories of Fawcett. They said Fawcett ignored their warning of traveling in the direction of "fierce Indians," and Grann concluded that Fawcett and his group were killed, rather than dying of starvation or disease. Regarding the lost city, he noted that recent aerial footage shows enormous geometric shapes diagrammed into the earth, and this may have been home to a large, ancient civilization."
http://www.davidgrann.com