The main feature of the Amazon River is its immense size and biodiversity. Stretching over approximately 4,345 miles (7,062 kilometers), it is the longest river in South America and among the longest in the world. The Amazon River flows through several countries, including Brazil, Peru, and Colombia, and supports the largest rainforest ecosystem on the planet. It is home to an astonishing variety of wildlife, including thousands of fish species, mammals, insects, and plants. Additionally, the river plays a crucial role in regulating the Earth's climate and influencing weather patterns in the region.