The small cruciform building standing near the massive Basilica of San Vitale and known as the Mausoleum of Galla Placidia was erected in the second quarter of the fifth century A.D. as a satellite building to the Church of Santa Croce, being situated at the southern end of the narthex of the Basilica which the Empress had previously built there.
The Mausoleum of Galla Placidia is one of the most extraordinary monuments of Late Antiquity which have come down to us, both for its architecture and decoration. Built to the shape of a Latin cross (m. 12,75 x 10,25) it has a plain bare exterior fabric of short and large bricks divided by a 2 cm layer of lime, a traditional feature in the architecture of the whole of North Italy.
Over the crossing of the two arms of the cruciform building is a dome made of bricks and concealed on the exterior by a small quadrangular tower. The interior of the Mausoleum displays a lavish amount of decoration: in its lower part it is covered by panels of yellow marble, whereas in its upper part it is completely covered with mosaics. The Mausoleum of Galla Placidia is part of the UNESCO World Heritage Site.