El Cervantino International Festival
Typically held in October.
Cervantino is considered the most important cultural festival in Mexico, and arguably, all of Latin America. It features artists from around the world performing music of all types, traditional and modern theatre events, film, dance, lectures, exhibits of visual arts and technology, children's activities and more. The 2011 festival boasted 2800 artists from 29 countries, performing in 49 venues across the city of Guanajuato alone. To see pictures of the events of 2011, go here. This will take you to the official website, although English may not be available. While based in Guanajuato, other cities host Cervantino events as well, including San Miguel de Allende.