Every week, embark with host Boyd Matson on an exploration of the latest discoveries and interviews with some of the most fascinating people on the planet, on National Geographic Weekend.

Please check listings near you to find the best way to listen to National Geographic Weekend on radio, or listen below!

Hour 1

– The first descent of the Amazon, from source to sea, was completed by Piotr Chmielinski and Joe Kane in 1989. But when a new source for the world’s second longest river was discovered years later, it appeared that the title of “first descent” was once again up for grabs. National Geographic Explorer West Hansen tells Boyd that the difficulty didn’t come in the Class V whitewater sections on the Mantaro River (the Amazon’s new headwaters, which make the river 50 miles longer than the original source on the Apurimac River); Hansen says that the most difficult part of the journey was the “final” 3,800 miles. He was held up at gunpoint three times on the descent, but didn’t find trouble from the river’s wildlife. He also says that the wide, flat sections toward the Amazon’s outlet at the Atlantic Ocean, while not as adrenaline-filled as the whitewater areas, “for the entire 111 days, there was not a boring day.” Listen here.