The longest river in South America is the Amazon River. Stretching approximately 4,345 miles (7,062 kilometers), it flows from the Andes Mountains in Peru through Brazil and into the Atlantic Ocean. The Amazon is not only significant for its length but also for its vast drainage basin, which is the largest in the world, covering about 2.7 million square miles. The river is home to an incredibly diverse ecosystem, supporting countless species and Indigenous communities who rely on it for their livelihoods. It is often referred to as the "lungs of the Earth" due to its role in carbon dioxide absorption and oxygen production.