Orinoco
Middle Orinoco —  long. The first part of this section has a general westward direction. It flows down to the confluence with the Atabapo and Guaviare rivers at San Fernando de Atabapo. The river then flows northward along the Venezuelan–Colombian border. On both sides of the river are the mountains of the Guiana Shield. The section ends at the Atures rapids, near the confluence with the Meta at Puerto Carreño.