By many estimations, the Amazon may be the world's mightiest river. It has the largest drainage basin in the world and is also the largest in terms of water volume.
Indigenous people have also been exploring the river for millennia. In more recent centuries, other explorers have sought to find the ultimate source of South America’s great river. These have included everything from European conquistadors nearly five centuries ago to more recent scientific explorations using modern technology.
While many of these expeditions have led to a wider knowledge about the vast hydrology of the Amazon, finding the definitive source of the Amazon River still remains an open question — similar to the ongoing exploration of the source of the Nile River in Africa. It depends largely on which branch you decide to follow, metaphorically and geographically. As such, scientists and explorers have argued for several different sources.
“The tricky thing about measuring the source of a river is the method you use dictates the result,” says Andrew Johnston, a manager at the Adler Planetarium in Chicago.
