The area is mostly flat and covered by dense rainforest, rivers, swamps, and mangroves.

The Baudó Mountains are a small, isolated range in this area along the coast.

Gorgona Island is located off the southwest coast.

From north to south the main rivers are the Atrato, San Juan, Calima, Dagua, Anchicayá, Sanquianga.

This region has the distinction of being one of the most biodiverse areas on the planet.