The St. Vitus Cathedral is a Roman Catholic cathedral in Rijeka. In the Middle Ages, the Church of St. Vitus was a small and one-sided, romanesque church dedicated to the patron saint and protector of Rijeka. It had a semi-circular apse behind the altar, and covered porch. With the arrival of the Jesuits in Rijeka, the Cathedral as we see it today was founded in 1638. First, it became the Jesuits' church. When the town of Rijeka became the center of the diocese, and then in 1969 the center of the archbishopric and metropolit, the representative Jesuit's Church of St. Vitus became the Cathedral of Rijeka. It’s a rotunda, which is unusual in this part of Europe, with elements of Baroque and Gothic, including fine baroque statuary inside. The cathedral is depicted on the reverse of the Croatian 100 kuna banknote, issued in 1993 and 2002.
References: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.