Meeting of Waters in the context of "Rio Negro (Amazon)"

The Amazon River (US: /ˈæməzɒn/; Portuguese: rio Amazonas, Spanish: río Amazonas) in South America is the largest river by discharge volume of water in the world, and the longest or second-longest river system in the world, a title which is disputed with the Nile.

The headwaters of the Apurímac River on Nevado Mismi had been considered, for nearly a century, the Amazon basin's most distant source until a 2014 study found it to be the headwaters of the Mantaro River on the Cordillera Rumi Cruz in Peru. The Mantaro and Apurímac rivers join, and with other tributaries form the Ucayali River, which in turn meets the Marañón River upstream of Iquitos, Peru, forming what countries other than Brazil consider to be the main stem of the Amazon. Brazilians call this section the Solimões River above its confluence with the Rio Negro forming what Brazilians call the Amazon at the Meeting of Waters (Portuguese: Encontro das Águas) at Manaus, the largest city on the river.

Manaus (Portuguese: [mɐˈnaws, ma-] ) is the capital and largest city of the Brazilian state of Amazonas. It is the seventh-largest city in Brazil, with an estimated 2024 population of 2,279,686 distributed over a land area of about 11,401 km (4,402 sq mi). Located at the east centre of the state, the city is the centre of the Manaus metropolitan area and the largest metropolitan area in the North Region of Brazil by urban landmass. It is situated near the confluence of the Negro and Amazon rivers. It is one of the two cities in the Amazon rainforest with a population of over 1 million people, alongside Belém.

The city was founded in 1669 as the Fort of São José do Rio Negro. It was elevated to a town in 1832 with the name of "Manaus", an altered spelling of the indigenous Manaós peoples, and legally transformed into a city on October 24, 1848, with the name of Cidade da Barra do Rio Negro, Portuguese for "The City of the Margins of the Black River". On September 4, 1856, it returned to the name "Manaus".

A whitewater river is classified based on its chemistry, sediments and water colour. Whitewater rivers have high levels of suspended sediments, giving the water a pH that is near-neutral, a high electric conductivity and a pale muddy, café au lait-like colour. Whitewater rivers are of great ecological importance and are important to local fisheries. The major seasonal Amazonian floodplains known as várzea receive their water from them.

The best-known whitewater rivers are Amazonian and have their source in the Andes, but there are also whitewater rivers elsewhere in South America and in other continents.