The Cathedral Basilica of the Holy Cross (Bazylika Katedralna Podwyższenia Krzyża Świętego) was built in the 15th century on the site where before there was a structure of the 11th and 13th centuries. It was rebuilt several times. With towers with a height of 73 meters is the tallest structure in the city. In the temple there is a painting of the Virgin of Opole, brought there permanently in 1702.
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.