The original wooden Most Holy Trinity church was built in first half of 17th century. The church was burned down few times. Current walled Most Holy Trinity Church was begun to build on 24 May 1766. From the original wooden church, only a tower (from 1628), a middle choir, an oratory and a sanctuary remained. The church was sanctified on 2 June 1770 on Most Holy Trinity day.
During the Second World War the church was targeted by mines. East part of roof was damaged, also the baroque altar. Innovation of left side baroque main altar was realized after 1945 by academic artist Ctibor Belan cooperate with benched master Jan Rakyta.
The church contains a monumental late-baroque altar, the Marian column (from late 18th century), the Sculpture of Saint John of Nepomuk (from late 18th century), and a folk sculpture of Saint Florian (from second half of 18th century).
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.