Why does the Congo River follow a counterclockwise arc across central Africa?

The Congo River follows a giant counterclockwise arc across central Africa primarily because it flows through a vast, shallow geological depression known as the Congo basin.12

This basin is characterized by a central depression—often called the cuvette—that is enclosed by an almost circular rim of highlands. The river’s path is dictated by the topography of this region, as it collects water from a fan-shaped network of tributaries flowing downward along concentric slopes toward the central depression.12

The river rises in the highlands of northeastern Zambia and follows this arc to the northwest, west, and southwest. Geologically, the basin has experienced a persistent tendency toward subsidence, while the edges of the cuvette have undergone uplifting, particularly on the eastern side due to the influence of the Western Rift Valley. Eventually, the river cuts through the highlands—specifically the Cristal Mountains—to reach the Atlantic Ocean via a relatively recent exit.3412