The Congo River basin is one of the biggest basins in the world. It is a big obstacle for people to move in this part of Africa because:
- It is surrounded by mountains
- It has enormous amount of water and rivers, and also almost daily precipitations, which makes it very hard for people to cross this part
- It has constantly high temperatures and huge amount of moisture in the air, and that makes it hard for people to function in this conditions
- It's covered with very dense vegetation, it is a tropical rain forest, and the terrain is more often than not steep, so the movement is almost impossible
- There's lots of dangerous animals that can easily harm or kill people.