The harbour had two large basins, now almost choked with sand.
The basins of the Parana and Paraguay are separated by low mountain ranges extending north from the sierras of Paraguay.
The climate is healthy in the uplands, though subject to violent changes; in the valleys fever is very prevalent, especially in the basins of the Boyana, the lower Drin and the Simen.
These saline basins extend down to the lower terraces of Cordoba, Mendoza and La Pampa.
The rivers of the province belong to the basins of the Indian Ocean and the Java Sea respectively, the water-parting being formed by the western and eastern ends respectively of the northern and southern lines of mountain peaks.