The Amazon River in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile.

The Amazon River is the deepest river in the world, with its depth varying dramatically along its 4,000-mile course. In its upper reaches and smaller tributaries, the river may only be 20 to 50 feet deep. However, as it enters the main basin in Brazil, the depth increases significantly. Near the "Meeting of the Waters" in Manaus, the riverbed can reach depths of 100 feet (30 meters). The deepest point of the Amazon is located near the city of Óbidos, where the river is constricted into a narrow channel only about 1.5 miles wide. Here, the water reaches a depth of approximately 330 feet (100 meters). This incredible depth is caused by the immense volume of water—roughly 20% of the world's freshwater discharge—moving through a relatively narrow space, which scours the riverbed over time. During the annual flood season, the water level can rise an additional 30 to 50 feet, flooding the surrounding rainforest and further increasing the total depth of the channel. This deep, navigable "trench" allows large ocean-going vessels to travel nearly 2,300 miles inland to Iquitos, Peru.