The longest river in the world is the Nile River, which stretches approximately 6,650 kilometers (4,130 miles). Flowing through northeastern Africa, the Nile runs through countries such as Uganda, Sudan, and Egypt before emptying into the Mediterranean Sea. Historically, the Nile has been crucial for the development of ancient civilizations, particularly in Egypt, where its annual floods provided fertile soil for agriculture. The river's significance continues today, serving as an essential water source for millions of people and playing a vital role in regional ecosystems. Research and debates about its length and tributaries often compare it with the Amazon River.