The monastery of San Martín Pinario is a Benedictine monastery founded in the 10th century. It is currently the Major Seminary of the archdiocese of Santiago de Compostela, the headquarters of the University School of Social Work, a centre attached to the University of Santiago de Compostela, as well as the headquarters of the Compostela Theological Institute. It is also home to the Diocesan Historical Archive of Santiago de Compostela.

It had its origins in an oratory dedicated to Saint Mary called de la Corticela, which was demolished at the end of the 9th century, except for the chapel, which today forms part of Santiago Cathedral, when King Afonso III the Great and Bishop Sisnando began the new cathedral building. Thus, around the year 899, this monastery was built, where the Benedictine monks moved from the old oratory. This monastery was later replaced by another monastery whose church was consecrated in 1102 by Bishop Diego Gelmirez, but not much remains from that period.

Throughout the Middle Ages the monastery grew to such an extent that by the end of the 15th century it had become the richest and most powerful monastery in Galicia. This led to it being almost completely rebuilt from the 16th century onwards. From that century onwards, it was the most powerful monastery in Galicia, with most of the Galician monasteries under its control.

With the disentailment in 1835 it was used for various functions and from 1868 it became the headquarters of the Major Seminary of the Archdiocese of Compostela.

The complex combines Renaissance, Baroque and Neoclassical elements. But fundamentally it is the great Galician Renaissance building, with a major reconstruction begun in the second half of the 16th century, definitively abandoning the Plateresque tradition whose end is symbolised by the works on the basilica of Santa María la Mayor in Pontevedra.

The façade has the structure of an altarpiece and shows the figures of the Virgin and Child and several Benedictine abbot saints. The Eternal Father presides over the triangular pediment. Saint Martin of Tours crowns the ensemble at the top with his most classical representation: on horseback and parting his cloak to shelter a beggar.

The church, completed in 1652, is the work of Mateo López y González de Araújo and opens onto the square that bears the name of the monastery, which slopes down towards it. The church has a single longitudinal nave, covered with a barrel vault with false coffers. Six side chapels open onto the nave, which communicate with each other and have the same type of vaulting as the nave. The transept is illuminated by a half-orange dome. The Baroque choir stalls are the work of Mateo de Prado and the three altarpieces of the main altar, together with the one in the Socorro Chapel of the same temple, are the work of Fernando de Casas y Novoa, who created here one of the most exquisite Baroque ensembles at a national and international level.