What is Qatar's longest river?
Which country has the longest river system in the world?
 The longest river in the world is the Nile River, which is approximately 6,650 kilometers (4,130 miles) long. The Nile River is located in Africa and flows through 11 countries: Burundi, Congo-Kinshasa, Egypt, Eritrea, Ethiopia, Kenya, Rwanda, South Sudan, Sudan, Tanzania, and Uganda.