The Nile River considered the longest river in the world, is approximately 4,258 miles (6,853 kilometres) long, but its exact length is a matter of debate. Flowing northward through the tropical climate of eastern Africa and into the Mediterranean Sea, the river passes through 11 countries: Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, Sudan and Egypt.
The Nile has two major tributaries: the longer White Nile, considered the prime stream and headwaters; and the Blue Nile, which carries about two-thirds of the river's water volume and most of the silt.
The White Nile begins at Lake Victoria, Africa's largest lake, which touches the countries of Uganda, Kenya and Tanzania. But Lake Victoria isn't necessarily the most distant and "true" source of the Nile River because the lake itself has many feeder rivers coming in from the surrounding mountains. In 2006, a British explorer named Neil McGrigor said he'd travelled to the Nile's most distant source at the beginning of the Kagera River, Lake Victoria's longest feeder river.
Still, experts do not agree which tributary of the Kagera is the longest — and therefore the most distant — source of the Nile. Ultimately, it would be either the Ruvyironza in Burundi or the Nyabarongo from the Nyungwe Forest in Rwanda.
