Basilica of San Vitale
The Chapel of the Holy Sacrament, also called the Day Chapel, is the only chapel within the Cathedral. It is in an octagonal form, borrowed from early Christian churches such as the Basilica of San Vitale in Ravenna. The number eight is considered a symbol of harmony. The roof has a caisson or rectangular grid form, similar to those of Romanesque cathedrals and some Italian churches, such as the Pisa Cathedral.