The Church of St. Donat (originally St. Trinity Church) is the most valuable monument of pre-Romanesque architecture of the early Middle Ages (9th century) in Croatia and the symbol of the city of Zadar. Because of its particular shape, it is one of the most important churches of its kind in Europe.

By construction type it follows the circular layout form of court churches of early Byzantine to the Carolingian period. However, because of its rough monumentality (height 27 and a width of 22 meters), unusual cylindrical form and double interior space, it distinguished itself by its originality. According to the legend, it was built by the Zadar bishop St. Donat in the 9th century. The church is mentioned in the famous 10th century paper “The administration of the state” by the Byzantine Emperor Constantine Porphyrogenitus. It was originally dedicated to the Holy Trinity. St. Donat name began to be used only from the 15th century.

Most of the architectural ornaments, as well as monolithic pillars in the church, have ancient origin and come mostly from the destroyed Roman Forum.

Today its space is used for musical performances, due to its extraordinary acoustic features (“Musical Evenings in Sv. Donat”).