Amazon

Amazon River in South America is the world's largest river by discharge volume of water and, in comparison to the Nile, the world's disputed longest river. The headwaters of the Apurmac River on Nevado Mismi had been thought to be the Amazon's most distant source for nearly a century until a 2014 study discovered that it was the headwaters of the Mantaro River on Peru's Cordillera Rumi Cruz. The Ucayali River is formed when the Mantaro and Apurmac rivers unite to produce the Ucayali River, which meets the Maraón River upstream of Iquitos, Peru, to form the primary stem of the Amazon for countries other than Brazil. The Solimes River runs above its confluence with the Rio Negro, producing what Brazilians call the Amazon at the Meeting of Waters in Manaus, the river's main city.

The Amazon River has an average discharge of around 209,000 m3/s, or 6,591 km3 per year, which is larger than the total discharge of the next seven greatest independent rivers. Two of the top 10 rivers in terms of discharge are Amazon tributaries. The Amazon accounts for 20% of worldwide riverine flow into the oceans. With an extent of approximately 7,000,000 km2, the Amazon basin is the world's largest drainage basin. The drainage basin of the river in Brazil alone is larger than that of any other river. Although the Amazon only has one-fifth of the flow it eventually empties into the Atlantic Ocean when it enters Brazil, it already has a bigger flow than any other river at this stage.

Total Length: 4,345 miles (shared with Brazil, Colombia, and Ecuador)