san fernando (in ) is the capital of the province of colchagua, in the central zone (central part) of chile. san fernando is the second most populated urban center of the region of o'higgins. it is located near to the tinguiririca river, in the valley of colchagua, san fernando is 1,112 feet (339 m) above the level of the se. san fernando was founded in 1742, and became the provincial capital in 1840.