The Valenciana Mine, known as Mina de La Valenciana in Spanish, is located in Guanajuato, Mexico. Valenciana is about 6 km from the Historic Center, Guanajuato, Guanajuato. La Valenciana Mine, Historic Guanajuato City, and surrounding mines are part of a UNESCO World Heritage Site. It began to exploit silver in the 16th century. Its extraction of silver was so abundant that its production was equivalent to two-thirds of the total that was obtained from this metal in all of New Spain. Currently, it belongs to the Santa Fe Cooperative Society of Metallurgical Mines of Guanajuato and continues to be exploited at a depth of 760 meters. History Although the mother vein of Guanajuato was discovered in 1548, the Valenciana mine reached its highest production levels from 1768 to 1804. The mine produced 60% of the world silver production in the 18th century. In 1760, the young Antonio de Obregón y Alcocer obtained a loan from the merchant of the Rayas mine, Pedro Luciano Otero. For several years, they both continued investing in the mine until in 1768 their production increased considerably. For several decades, the La Valenciana mine produced more silver than all the mines in the Viceroyalty of Peru, being Obregon's partners, Messrs. Otero and Diego Rul. On 20 March 1780, the King Charles III of Spain – at the request of the Viceroy Antonio María de Bucareli y Ursúa – granted Obregón the titles of Viscount de la Mina and count of La Valenciana, located in Guanajuato, Mexico. In 1788, his son Antonio Alonso de Obregón and de la Barreda succeeded him. Although he inherited the titles, the property of the mine was divided into twenty-four shares, the descendants of Obregón kept ten shares, the family of Otero twelve shares and the family of Juan Antonio de Santa Ana two actions. On 8 August 1803, Alexander von Humboldt visited the mine, according to his "Political Essay on the Kingdom of New Spain" the mine had "given its owners four hundred to six hundred million pesos, at least, of annual utility." During its good years, more than three thousand workers were employed. In 1803, the mine was exploited to a depth of 185 meters; in 1810, its production was suspended. By 1815, the depth reached for its exploitation was 514 meters. In 1810, during the beginning of the War of the Independence of Mexico, most of the miners participated