Inside, the basilica is built in richly carved white marble. It consists of a
nave and two aisles with arches supported by
columns with Roman and Romanesque
capitals. The Roman capitals were recycled from the nearby Roman
amphitheatre. The highlight at the entrance is the huge 12th-century Romanesque baptismal font (the
Fonte Lustrale). It is composed of a bowl, covered with a
tempietto, resting on pillars, inside a circular basin. It is the craftmanship of master Roberto (his signature is on the basin) and two unknown masters. The basin is decorated with
The Story of Moses by a Lombard sculptor. Master Roberto did the last two panels
The Good Shepherd and the
Six Prophets. The tempietto was sculpted by a Tuscan master, representing the months of the year and the apostles. Behind this font, higher on the wall, are two 15th century
glazed terracotta lunettes:
The Annunciation and
St. Bartholomew, both attributed to the school of
Andrea della Robbia. There is another baptismal font, still in use, carved and adapted from a sacramental altar by
Matteo Civitali in 1489. The counterfaçade houses the 16th century
organ in the exquisitely carved, gold-plated choir from the 17th century. On the right hand is the side chapel of St.
Zita (c. 1212–1272), a popular saint in Lucca. Her intact incorrupt body, lying on a bed of brocade, is on display in a glass shrine. On the walls of the chapel are several canvasses from the 16th and 17th centuries depicting episodes from her life. The remains of St. Frediano lie underneath the main altar from the 16th century. A massive stone
monolith stands left of the main altar. This was probably pilfered from the amphitheatre of Lucca. But local tradition has it that it was miraculously transported to Lucca by San Frediano and used as a
predella (step of an altar) for the first altar. ==Chapels==