The present
nave preserves its original (pre-12th century) basilica plan and stands on the earlier foundations. The 22 granite columns with
Ionic and
Corinthian capitals that separate the nave from the aisles came from the ruins of the
Baths of Caracalla, as did the lintel of the entrance door. When scholarship during the 19th century identified the faces in the carved decoration of the capitals as
Isis,
Serapis and
Harpocrates, a restoration under
Pius IX in 1870 hammered off the offending faces.
Domenichino's octagonal ceiling painting,
Assumption of the Virgin (1617) fits in the coffered ceiling that he designed. Below are mosaics on the subject of the "
Life of the Virgin" by
Pietro Cavallini (1291). In the Capella Altemps there is a unique icon of the enthroned Virgin and Child "The
Madonna della Clemenza", a panel painting in
encaustic, dated between the 6th and 9th century CE, probably of Byzantine origins. The Madonna della Clemenza is one of the five oldest existing Marian Icons from the medieval period. Its proximity to the rise of Christianity is one of the reasons it was believed to be a divine image. The fifth chapel to the left is the Avila Chapel designed by
Antonio Gherardi. This, and his Chapel of S. Cecilia in
San Carlo ai Catinari are two of the most architecturally inventive chapels of the late-17th century in Rome. The lower order of the chapel is fairly dark and employs
Borromini-like forms. In the dome, there is an opening or
oculus from which four
putti emerge to carry a central
tempietto, all of which frames a light-filled chamber above, illuminated by windows not visible from below. Complexively, four different types of direct and indirect lighting are placed into the borders of a small space of a "pre-built side-chapel facing south along the left side-aisle of the medieval church", producing a unique "instance of the scenic use of light in baroque architecture." In the first chapel of the right nave there is
Santa Francesca Romana by
Jacopo Zoboli. The church keeps a relic of
Saint Apollonia, her head, as well as a portion of the
Holy Sponge. Among those buried in the church are
Pope Callixtus I,
Pope Innocent II,
Antipope Anacletus II, Cardinal
Philippe of Alençon and Cardinal
Lorenzo Campeggio. ==The titulus==