Built outside the Roman city walls, near the amphitheater from which it has taken most of its salvage materials, this extremely old religious building is of great importance not only for art history but also for all sacred Western Christian architecture. It can be compared to San Vitale of Ravenna and the Aquisgrana cathedral. It went through numerous renovations through the end of the fourth century and the beginning of the fifth century, and today has a sixteenth century style in features such as the dome. There are also features left over from the early Christian era such as the main building, the four towers, some lateral chapels and the foundations formed of enormous blocks taken from other Roman sites. The interior walls were probably covered by marble lower down and by mosaics higher up depicting sacred scenes and saints. On the right there is a stupendous rectangular portal from the Roman era which leads to the chapel of Sant'Aquilino, which is octagonal and holds a tomb with the remains of St. Lorenzo and St. Ippolito. Some say this is an imperial mausoleum. After many interventions in the nineteenth century, the church was restored to it's current state between 1937 and 1938. There is a legend that the chapel was built by Galla Placidia, and it is thought that she is buried in the tomb on the right of the entrance. Outside there is a statue which is a copy of the statue of Constantine, who was made Emperor in 313, and gave freedom to the cult of Christianity. Also to be noted is the umbrella shaped dome and fragments of early Christian mosaics.