A pongo (corruption of the Kichwa punku and the Aymara punku, meaning a door) is a type of canyon or narrow gorge along rivers in Peru, especially on the Marañón River (Upper Amazon) and its affluents, in the Amazonas Region.
See:
Pongos in Amazonas, the big pongos of Marañón RiverThe Amazonas Region, home to pongosThe Pongo de Manseriche, gorge in northwest Peru where the Marañón River runsThe Pongo de Mainique, most dangerous whitewater pass on the Urubamba RiverThe Olmos-Marañon Route, transcontinental road, includes the "route of pongos"The Marañón River, has 35 miles of pongos before the Amazon RiverThe Huallaga River, crossing the Andes forming the Pongo de Aguirre