Reasons to study Spanish in Guanajuato. THE CITY: 1  Population: 160,000. 2  The city of Guanajuato is the state capital of Mexico's Guanajuato State and one of the most important historical and cultural colonial cities in Mexico. 3  Guanajuato is located in the central part of Mexico, south of the high Mexican plateau. 4  In 1988, UNESCO declared Guanajuato and its surrounding silver mines a 5  ... Th