Most rivers never cross the Equator.
The Congo River does it twice.
The river follows a huge curved path through Central Africa. Along the way, it flows from one side of the Equator to the other and then crosses it again.
So why does the river take such an unusual route?
Why does the Congo River cross the Equator twice?
The answer comes down to geography.
The Congo River flows through the vast Congo Basin. This basin covers a large part of Central Africa and extends across both sides of the Equator.
Water from a huge network of rivers and streams flows toward the Congo.
However, the river does not simply travel in a straight line toward the Atlantic Ocean.
Instead, the shape of the land guides it through a broad curve.
This route takes the Congo across the Equator twice before it eventually reaches the Atlantic.
A river on both sides of the Equator
The unusual route has another interesting effect.
Different parts of the Congo Basin experience their rainy seasons at different times.
Areas north and south of the Equator do not always receive their heaviest rainfall during the same months.
As a result, water can enter the Congo River from different parts of its enormous basin throughout the year.
This helps support its powerful flow.
One of the world’s most powerful rivers
The Congo is remarkable for more than its unusual route.
It has one of the largest river basins on Earth.
It is also the world’s second-largest river by water discharge, behind the Amazon.
Scientists have measured extraordinary conditions in the Lower Congo.
Research by the US Geological Survey found depths of more than 200 metres in some areas.
Researchers also measured water speeds above four metres per second.
The Lower Congo contains deep pools, rapids and powerful currents.
An unusual journey across Central Africa
The Congo River eventually reaches the Atlantic Ocean on Africa’s western coast.
Before getting there, however, its enormous curved route takes it across the Equator twice.
That makes the Congo one of the world’s most geographically unusual major rivers.
A line that circles the entire planet crosses the same African river not once, but twice.