The historic quarter of the city is located on the higher side of the hill. Its monuments include the church of Santa María la Mayor, from the 16th century (although some evidence suggests that it dates back to the 13th century); the conventual church of Madre de Dios, founded in 1510, and the old castle-citadel, from the 9th century, with several gateways to the walled enclosure. At the square Plaza de la Constitución, next to the office buildings, we find the house of Monte, from the 18th century, and adjacent to the square, the house of Tercia, from the late 18th century, which at present houses the Municipal Museum of History.