The central nave is the oldest part of the Basilica, completed in 1908. The Basilica has the shape of a latin cross, with a single nave. It is 32 meters long, including the choir. It is 11.50 meters wide and 25 meters high. Including the transepts is 40 meters long overall.
There are six side chapels, leading to the High Altar and the throne of the Infant Jesus. From the right they are: Chapels of St. John of the Cross, St. Theresa of Jesus Christ, and St. Joseph; on the left, Chapel of the Passion, of St. Theresa of Jesus, of the Sacred Heart and the Mother of Mount Carmel.
The ceiling is a barrel, richly adorned and has two beautiful medallions by Marigliani of Bergamo. These were the first decorations in the church and depict the adoration of the Magi and Jesus among the teachers in the temple.
In the center of the vault there are four ovals, depicting four devotees of the infancy of Christ: St. Albert of Sicily, Ven. Francis of Infant Jesus, Ven. Margaret of Most Holy Sacrament and Bl. Maria of Angel.
The vault narrows in close proximity to the presbytery and forms a triumphal arch, on which we find the coat of arms of the order placed in the center, surrounded by sculptures: St. Elia and St. John of the Cross (left) St. Theresa of Jesus and St. Angel Martyr (right).
The vault narrows near the presbytery and forms a triumphal arch, on which we find the emblem of the Order placed at the center, surrounded by busts: St. Elias and St. John of the Cross (left) St. Teresa of Jesus and S Martyr Angel (right).
At the top of the entrance wall you can admire the splendid rose window by the Balmet company from Grenoble. With its 4 m of diameter it gives light to the whole Basilica and represents the mystery of the Incarnation of the Word. In the center is represented the Infant Jesus and the sixteen petals of the “flower” form a cross in the midst of which the twelve mysteries of the Infancy of Jesus are divided into groups of three. On the sides of the rose are two frescoes depicting the Princess Polissena that donates the statue to the Carmelites and the Healing of the Countess Kolowrat.
Another four windows, also by Balmet, are arranged along the nave and depict the prophets who predicted the birth of the Messiah: David and Isaiah (right), Jeremiah and Daniel (left).
The counter-façade is occupied by the great majolica of Biancini, depicting the mystery of the Incarnation and other episodes related to the Infant Jesus.