Salamanca is a city in the Mexican state of Guanajuato. Founded January 1, 1603 as 'Villa de Salamanca' by the Viceroy Gaspar de Zuniga and Acevedo, fifth Earl of Monterrey, who was originally from Salamanca (Spain). The town was founded in the lands of Bajio, after cattle ranchers and poor farmers, a few Spaniards, and small groups of Otomi Indians who formerly occupied a village named Xidoo, already lived in the area. In recent years, many refineries have opened, and Salamanca has grown rapidly to become an important site for manufacturing and service industry in the region.