The atrium on the north side, since the 15th century, was used for the two existing chapels, founded by noble houses. For its construction it was necessary to lower the ground, in order to bring it to the level of the interior enclosure, and also open the arches of the respective Chapels in the walls of the primitive Mozarabic enclosure.

- CHAPEL NUMBER ONE.

It is attached to the left arm of the transept and was originally a sacristy. When the one built in the 18th century was demolished, it has returned to its original purpose. On its simple stone entrance you can see the coat of arms of the founders. It is rectangular in shape, covered with a half-barrel vault and below it has a sepulchral crypt, in which burials are still carried out. Under the vault there is a sign that says: "This chapel and pantheon of the Honorable Marqueses of Miranda de Ebro, bought for himself and his successors in his majority the Licenciado Antonio de Junguita and his wife Mrs. Ginés Gimilio Vera. Year of N. Sr. Jesus Christ of 1668. Part of this inscription has been redone recently.
On the front of the chapel there is an altarpiece from the 17th century, very similar in style to the largest in the temple. It has two bodies and is golden and polychrome. The first body has two Solomonic columns and, in the center, a 17th-century canvas of the Immaculate Conception over an angel. well executed, and restored in the 19th century by the Segovian painter Mariano Quintanilla. On the sides there are two richly polychrome shields with the arms of the Junguito, Astara, Guevara and Falconi family.
The second body of the altarpiece is semicircular in shape, to adapt to the vault, and frames the oculus that gives light to the enclosure; It has two columns with their pseudo-composite and grotesque capitals richly carved and polychrome.
The bench of the altarpiece is marbled and the same was the altar table, which was withdrawn to place the drawers of ornaments.
In the sacristy, the following artistic objects are noteworthy:
Canvas from the 16th century, black frame, depicting Jesus Christ with the globe and inscription "Salvator Mundi"
Another canvas with the same characteristics and period as the previous one, representing the Virgin, with a book, and the inscription "Sancta
Maria mater Dei"Crucifix of carving of good execution, wood, 18th century, with base and skulls and bones.
Castilian bargueño from the 18th century. Three large drawers of ornaments, with bronze fittings. In 1687, in order to raise funds to help the work of the main chapel of the temple, the patronage of this chapel was granted to the Junguito Family. The "Ceballos Escalera" continue the Board of Trustees of this Foundation. On July 9, 1827, Mr. Cayetano Peñalosa, Brigadier of the Army, was buried in the chapel, and in 1905, Mrs. Julia Meléndez, Marquesa de Miranda...

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- CHAPEL NUMBER TWO.

In it there is a room where the heating and other services are located. In one of its corners it has a bracket to start a Gothic vault with the letters JHS. Was this chapel only begun? He disappeared?..

- CHAPEL NUMBER THREE. 

It is the famous chapel of the Marquises of Herrera. It has a flowery Gothic-style doorway, which could be attributed to the "GUAS", very similar to others in the Monastery of El Parral.
It is made of white limestone and is missing the two statuettes it may have had in the canopies. At the top it bears the shields of the founding family.
The arch appears framed by two frets: The outer one represents life in the world, with oak leaves, and among them are the human arts, with a man working with a hammer, another hunting, etc.
The interior fret represents spiritual life, and has the typical thistle leaves, which represent the sacrifice of living God's law.
It has doves nibbling on bunches of grapes, the deer and several pelicans feeding their young. All of them are Eucharistic symbols.
The wooden rack, recently restored, is also very similar to others in El Parral. The vault is Gothic ribbed, with five false keys and golden pendants, some of them with the shields of the founding family. Under the vault there is an inscription in Gothic letters with blue and gold tones, which says:
"This chapel was ordered by the honorable landlord Gonzalo de Herrera, and servant of the very high and very powerful prince King D. Fernando our lord, who called him a knight of golden spurs in combat in the city of Ronda; and he gave it to the factory thousand maravedies in weight and two chickens: and left two Masses each week"On the pavement there is a tombstone that says: "Here lies D. Antonio de Herrera and Doña María de Cuéllar
Bonifaz, his wife. He died on August 17, 1671. They provided a chaplaincy in this chapel with six masses each week and the aforementioned died on September 3, 1673.

CHAPEL NUMBER 4 

It is the chapel of San Ildefonso, and at the entrance there is an arch with two Doric semi-pilasters and cornices, a split pediment, and in the center of it the oval shield of the founders, with their dragantes. The gate at the entrance is simple, made of wood, and the vault has lunettes, and on the cornice there is a cartouche that says:
"This chapel was founded by Alonso Moreno, Treasurer who was of the Royal Ingenuity of the Casa Baxa de la Moneda of this city" It cost 180,000 Mrvds on its site. He died on August 1, 1569.

This chapel is connected today with the previous one by a semicircular arch that was blinded before. Currently in these chapels there is a parish museum, inaugurated in 1985.