The mausoleum is divided into two decagonal orders, one above the other.

Built before or around the time of Theodoric's death in 526, this unique building demonstrates the remarkable degree of artistic originality that persisted in Ravenna while it was still an Ostrogothic town. It is a two-storey structure built of huge blocks of ashlar without mortar and crowned by a flat-domed monolithic roof (diameter 11 m) weighing about 300 tonnes. Externally each of the ten sides of the lower storey has a deep arch resting on half piers. It is the only surviving example of a tomb of a king of this period. One of eight Ravenna sites on the UNESCO World Heritage List.