Ravenna, Mausoleum of Galla Placidia

The Mausoleum of Galla Placidia is a Roman building in Ravenna, oiginally the oratory of the Church of the Holy Cross.

See:

1. Andre Grabar, L'Âge d'or de Justinien, de la mort de Théodose à l'Islam, Paris 1966
2. https://en.wikipedia.org/wiki/Mausoleum_of_Galla_Placidia