Morphology of the continental platform (Isla Fuerte – Cartagena). There is a wide platform with a great many islands and archipelagos of coral origin. It has a low relief bordered in large part by mangrove forests associated to deltas (Cispatá, Barbacoas and Cartagena) and sandy and muddy beaches. At the level of Tierra Bomba, on the western side, there is a rocky coastline, which originated from ancient coral reefs that rose in the Pleistocene.