Fodor's Expert Review Basilica

The highlight here is the spectacular 3rd- to 4th-century mosaic covering the entire floor of the basilica and the adjacent crypt, which make up one of the most important early Christian monuments. Theodore, the basilica's first bishop, built two parallel basilicas (now the north and the south halls) on the site of a Gnostic chapel in the 4th century. These were joined by a third hall, forming a "U." The complex later accumulated the Romanesque portico and Gothic bell tower. The mosaic floor of the basilica is the remains of the floor of Theodore's south hall.

In his north hall, Theodore retained much of the floor of the earlier Gnostic chapel, whose mosaics represent the ascent of the soul, through the realm of the planets and constellations, to God, who is represented as a ram. (The ram, at the head of the zodiac, is the Gnostic generative force.) This integration of Gnosticism into a Christian church is interesting, since Gnosticism had been branded a heresy by early church fathers.

The 4th-century mosaics of the south hall (the present-day nave) represent the story of Jonah as prefiguring the salvation offered by the Church. Down a flight of steps, the Cripta degli Affreschi contains 12th-century frescoes.