Ferdinand the Catholic donated money towards its construction. The architects were Juan de Orozco (the church), Martín de Villarreal (the front) and Juan de Badajoz (cloister and sacristy). It has the longest Plateresque (Spanish Renaissance) façade in Spain. It is a single stretch of wall on two levels, topped out with pierced cresting and candelabra. The lower storey is decorated with medallions of Graeco-Lating and Spanish historical personages, and the upper one is adorned with heads of angels.
Built in 1711-1714, it has a great plinth. It is decorated with the cross of St James and a lion and has four friezes and an entablature.
This has two tiers and a peineta. The lower storey has a large semicircular arch with a rosette and decorated soffit. The keystone, which stands out, has an effigy of St Mark (San Marcos). Medallions contain Biblical inscriptions, a high relief of St James triumphant and the Battle of Clavijo. The light is in the Baroque style, with the coats of arms of St James and the Kingdom of León. The peineta, by the Valladolilds, bears the royal arms and a statue of Fame. The oculus is shaped like a rose window.
Two sides were built by Juan de Badajoz the Younger in the 16th century, one of them containing a relief by Juan de Juni of the Nativity. The other two walks were built in the 17th and 18th centuries. The entrance is flanked by two unfinished towers and has a great ribbed vault. There are two reliefs: a Calvary scene and the Descent from the Cross by Juni. The interior is a spacious hall with a transept closed off by a grille. The main reredos shows the Apostles and the Annunciation (18th century).
The lower part was made by Guillermo Doncel in the 16th century, and the rest by Juan de Juni.