The primary river running through Brazil is the Amazônia River, which is the second-longest river in the world. The river spans approximately 4,345 kilometers and flows through several countries, including Peru and Colombia, before emptying into the Atlantic Ocean. The Amazon River is renowned for its vast rainforest ecosystem, which is critical for the planet's biodiversity. It also serves as a vital transportation route, supports local communities, and is essential for the regional economy and ecology.