Church of the Christ

The lower and older church, now the crypt, often referred to as the Iglesia del Cristo, or "Church of the Christ", contains a nave and two aisles. Its dimensions are 31 metres long and 18 metres wide. The whole vaulted structure supports the weight of the upper floor, which explains the thickness and robustness of the construction. Its decoration consists mainly of plant-like ornaments.

Cathedral-Basilica of Santander

The principal church of this monumental complex was built during the 13th century in the same simple Gothic style that had been used for the preceding Church of the Christ. It lost most of its treasures in the above-mentioned fire of 1941, although some survived and others were later recovered. Most of the decoration of the arches, columns, entablature and doorways is preserved. The portal with the coat of arms of Castile and León is specially important. The windows are decorated with stained glass, although it is modern.

The cathedral has numerous chapels distributed along the walls of the two side aisles to the north and south. To the south, the first chapel is the work of Fernando Herrera Calderón dating from 1624; the second one was made by Juan Alvarado in the 17th century; the third one is by Sebastián de la Puebla, and dates from 1622. To the north, the first chapel is from 1671, and has Baroque characteristics; the second one is the Penitence Chapel and contains a baptismal font; and the third one holds the tomb of Marcelino Menéndez Pelayo sculpted by Victorio Macho.

Due to the reconstruction project, many important Baroque elements were suppressed that had formed an extension to the church and were the work of José de Cereceda dating from the 18th century.

The church was expanded in the middle of the 20th century by the addition of a new presbytery and ambulatory. In order to build these new elements, the stone choir that had survived the fire, the Martyrs' Door and the monumental stairs had to be removed. The choir had been constructed by Francisco del Pontón Setien and Juan de la Sierra Bocerraiz, and the other items were the work of Gregorio de la Roza dating from the 17th century. These last were disassembled and their building stones numbered for later reconstruction, but their location ever since has been unknown.

The presbytery is surrounded by the ambulatory, which contains two altars devoted to Saint Fernando III of Castile and to Saint Matthias. It is also accompanied by a piece of marble with carvings in Arabic, supposedly taken in the assault on Seville. In the southern flank there is a tribune decorated by José Cataluña. The vaults are simple groin vaults, whose slenderness is magnified by the light coming from the clerestory in the wider and higher central nave.

The old collegiate church consisted of three naves, with a fourth one being added from the space formerly occupied by the abbot's palace and other chapels. Between the 15th and 17th centuries several side chapels were added to it.

The cloister, with a trapezoidal shape, was built during the first half of the 14th century in the same architectural style. Through the doors of its western wall, it was possible to access the great Hospital of the Holy Ghost and the pilgrims' church on the Way of St. James.