Reggio Calabria Castle was originally built before 540 AD and enlarged by the Normans and later by the Aragonese in 1459. Throughout the centuries it has been restored and enlarged by its conquerors.
The building began to decay in the very early 19th century. Various collapses and demolitions had dotted its history until the recent and radical restoration that brought it back to its original splendor. Today it is the seat of expositions and art exhibitions.
The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.