The Amazon rainforest is located in northern and central South America, primarily within the enormous Amazon Basin. Its greatest extent is in Brazil, which contains the majority of the forest, but the rainforest also extends into Peru, Colombia, Bolivia, Venezuela, Ecuador, Guyana, Suriname and French Guiana. The forest lies mainly within the tropical latitudes of the Western Hemisphere and is crossed by the Equator in several places. It occupies a broad region between the Andes Mountains to the west and the Atlantic Ocean to the east. The exact geographical extent depends on the definition used because terms such as Amazon rainforest, Amazon biome and Amazon Basin describe related but nonidentical areas.
Brazil contains the largest share of the Amazon rainforest and much of the Brazilian Amazon is located in the northern and western parts of the country. Major Brazilian states within the Amazon region include Amazonas, Para, Acre, Rondonia, Roraima, Amapa, Tocantins and Mato Grosso, although not all territory in every one of these states consists of rainforest.
Manaus is a major urban centre within the Brazilian Amazon and lies near the meeting of the Negro and Solimoes rivers, which form the Amazon River downstream. Belem, located closer to the Atlantic coast, is another major city historically connected with Amazonian commerce. The Brazilian portion of the forest is therefore geographically enormous but contains substantial variation in landscape and land use.
Peru contains the second largest national share of Amazon rainforest after Brazil. The Peruvian Amazon occupies much of the country's eastern lowlands beyond the Andes and contains major rivers including the Ucayali, Maranon and Madre de Dios systems. Cities such as Iquitos and Puerto Maldonado are important centres within or near Amazonian rainforest environments. Iquitos is particularly notable because it is a major city without a conventional road connection to the rest of Peru, making river and air transportation especially important. The Peruvian Amazon contains extensive protected areas and Indigenous territories and includes ecosystems ranging from lowland rainforest to transitional environments near the Andes.
Colombia, Bolivia, Venezuela and Ecuador also contain significant portions of the Amazon rainforest. In Colombia, Amazonian territory includes extensive forest landscapes around the Amazon, Caqueta, Putumayo and Guaviare river systems. Bolivia contains large rainforest areas in departments such as Pando, Beni and parts of La Paz and Santa Cruz. Venezuela contains Amazonian forests south of the Orinoco region, including landscapes associated with the Guiana Shield. Ecuador contains a comparatively smaller but biologically important portion of the western Amazon, particularly in the provinces east of the Andes. These national portions differ substantially in elevation, rainfall, geology, infrastructure and conservation status.
Guyana, Suriname and French Guiana form an important northern section of the Amazonian region. Their forests are influenced by the Guiana Shield, one of the ancient geological regions of South America. French Guiana is an overseas department and region of France and therefore has a different political status from the independent states of Guyana and Suriname, but geographically all three lie within the wider Amazonian environment. Much of the land in these territories remains forested, although development, mining, roads and settlements have altered some areas. The northern Amazon is therefore politically divided among several jurisdictions despite ecological systems crossing national borders.
The western boundary of the Amazon rainforest is strongly influenced by the Andes Mountains. The Andes rise dramatically above the lowland Amazon Basin and affect rainfall, river drainage, sediment transport and climate. Many Amazonian rivers originate in or near the Andes and flow eastward across the lowlands toward the Atlantic. The transition from Andean montane forest to lowland Amazonian rainforest is gradual in many places and includes highly diverse elevation zones. This relationship is particularly important because material eroded from the Andes is transported downstream, contributing to soils and sediments in parts of the lowland basin.
The eastern boundary of the Amazon rainforest approaches the Atlantic Ocean through the enormous river mouth and coastal systems associated with the Amazon River. The forest does not simply terminate at a perfectly defined line at the coast because surrounding ecosystems include wetlands, mangroves, savannas and transitional forests. The Atlantic supplies moisture to the basin through atmospheric transport, while river discharge returns enormous quantities of freshwater to the ocean. The interaction between ocean, atmosphere, rivers and vegetation helps maintain the regional hydrological cycle.
The Amazon rainforest should therefore be located geographically as a transnational tropical forest system in northern South America, centred on the Amazon Basin and extending across several countries and territories. It is not synonymous with Brazil, although Brazil contains the largest share, and it is not synonymous with the entire Amazon Basin because the basin includes areas that are not rainforest, including savannas, wetlands, mountains and other ecosystems. Likewise, the Amazon River is only one component of the broader Amazonian geographical system. Precise descriptions should therefore distinguish the rainforest biome, the drainage basin and the wider Amazon region.
