Centre Charlemagne is the new museum of Aachen local history. It occupies the site on the Katschhof, the former palace courtyard. It focuses on a history of Aachen from the Neolithic to the present day. The key periods are the ancient Roman age (until 4th century AD), Charlemagne's Aachen (the capital of Frankish Empire), the medieval period and Baroque period. The whole house is barrier-free.
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.