Byzantine

Dedicated to St. Apollinarus (Ravenna's first bishop), this 6th-century basilica is known for its two rows of ancient mosaics that stretch the length of the nave, telling biblical stories.

This mausoleum was built for one of the most powerful women in western history, although she was probably never buried here. It is filled with splendid Byzantine mosaics and marble tombs from the early 5th century.

Built in 548, this octagonal brick church contains some of the most celebrated Byzantine mosaics in the West.

Now an isolated ruin, this 5th-century Byzantine church was dedicated to the famous St. Sergius, a Roman soldier martyred c.303. The church was a major pilgrimage site in the Byzantine era.

Santa Sabina is the best surviving example of an early Christian church in Rome. It dates from about 430, including its magnificent cypress doors carved with biblical scenes.

A hidden gem near Santa Maria Maggiore, this 9th-century basilica has glorious Byzantine mosaics. Also here is a piece of the scourging column of Christ and other relics.

The church of Santa Maria in Trastevere is said to be the first place of Christian worship in Rome, built where a fountain of oil sprung up on the day of Christ's birth. Inside are many excellent Byzantine mosaics.

This major pilgrimage basilica features a columned portico, 6th-century mosaic, catacombs, and lovely 12th-century cloister. It is dedicated to Lawrence, who was martyred by roasting on a gridiron.

Also known as the Lateran Baptistery, this octagonal structure in Rome was built by Constantine in 315 and is the oldest baptistery in the world.

This ancient church in the Forum contains ruins of a Roman temple (which can be viewed through a glass wall) and important Byzantine mosaics.

Located in the Duomo's crypt, Milan's treasury displays a magnificent collection of Early Christian and Romanesque artworks, including ivory book covers with biblical scenes, reliquaries, and vestments.

Built on the site of a miraculous August snowfall, this major basilica dates from the early 5th century. The huge church is lined with Byzantine mosaics and contains many important relics.