Amazon–Ucayali–Tambo–Ene–Apurímac is the largest river by drainage area in the world at 7,050,000 km2.
The river system, from Amazon River to Ucayali to Tambo to Ene and Apurímac river, is the longest river system in South America at 6,992km (4,344 miles), with its drainage area spreading across the width of the South American continent at an area of 7 million square kilometers (largest drainage basin in the world!). The Amazon river system is also the second longest in the world, with the Nile River system pipping slightly ahead at 7,088km.In terms of discharge volume, the Amazon river system is the largest in the world, discharging at 209,000 cubic meters per second onto the Atlantic Ocean.