The Feria Nacional de San Marcos (National Fair of Saint Mark) is a national fair held in the Mexican state of Aguascalientes every year for three (or sometimes four) weeks. Most of the events occur in the city of Aguascalientes, the state capital. The exact date of the fair varies every year, but is set around April 25, the Feast Day of St. Mark.
Initially the fair was tied to the vendimia (harvesting of grapes) since wine production used to be an important activity in Aguascalientes. Nowadays, it is an important tourist attraction that is heavily associated with bullfighting and cockfighting. It is estimated that seven million people visit the fair every year and as a consequence hotels are usually filled to capacity. Some locals rent out their houses to visitors and go on vacation during this time.