Of the port of Buenaventura, on the Rio Cali, a small branch of the Cauca.
A railway from Buenaventura will give Cali and the valley behind it, with which it is connected by over 200 m.
The principal rivers of this group, starting from the southern frontier, are the Mira, Patia, Iscuande, Micai, Buenaventura or Dagua, San Juan and Baudo.
So difficult is the country through which the Cauca has cut its tortuous course that the fertile upper valley is completely isolated from the Caribbean, and has no other practicable outlet than the overland route from Cali to Buenaventura, on the Pacific. The upper sources of the Cauca flow through a highly volcanic region, and are so impregnated with sulphuric and other acids that fish cannot live in them.
The former has been of slight service in the development of the country because of the unsettled and unhealthy character of the coast region, and the high mountain barriers between its natural ports and the settled parts of the republic. There are only two commercial ports on the coast, Tumaco and Buenaventura, though there are several natural harbours which would be of great service were there any demand for them.