This is the answer to Yolanda Rubio´s question: Cochinchina is a region that corresponds to the southern region of modern Vietnam (country coloured in green on the map above). In the 16th century the Portuguese gave the name Cauchichina to the region around the mouth of Mekong river. "Cauchi" could be derived from "Jiao zhi", the name the Chinese gave to Vietnam. The Portuguese added "China" to "Cauchi" to distinguish this place from another colony called "Cochin" they had in India.
During the 2nd half of the 19th century Cochinchina became a French colony. Napoleon III decided to occupy this territory, with the help of the Spanish army, arrived from the Philippines. This is the origin of the Spanish expression "Eso está en la Conchinchina", meaning a very far and exotic place.
Here you have some more information about Cochinchina: