The Fiesta Nacional de España is the National day of Spain. It is held annually on October 12 and is a national holiday which commemorates the day in 1492 when Christopher Columbus first set foot in America. As such it is related to the Columbus celebrations held on the same day and for the same purpose across the Americas.
To commemorate it, there is a parade led by the military (usually held in Madrid) presided by the Spanish King, who is the Head of State, since Spain is politically organized as a constitutional monarchy. The Presidente del Gobierno has also a special role in the ceremony, only second to that of the King. Then a wide array of authorities, from foreign diplomats deployed in Spain to members of the Autonomous governments, are invited to attend the parade and aerobatics performed by the Spanish Armed Forces, typically by the Patrulla Águila.
In the Autonomous Community of Aragon, this date also commemorates Our Lady of the Pillar (their patroness). It is also observed by the Civil Guard.