Santi Primo e Feliciano church at the site is documented since the 12th century. It belonged to a college of canons regular who in 1354, became members of the Congregation of Servants of Mary, and so remained till the 18th century. The convent was suppressed in 1810.
The original structure had three naves, but in the 15th century an additional nave was added. In the 16th century, the church was reduced to a single nave, with demolition of the prior apse. The facade was restored in 1940.
The first chapel on the right has a Virgin and child with Blessed Bertoni and St John the Baptist (1498) by Agostino da Vaprio. The superior lunette has a fresco depicting God the Father. The transept has a large canvas depicting the Martyrdom of St Lawrence by Marcantonio Pellini (1664-1760). The presbytery has two lateral frescoes depicting the Life of Saints Primo and Feliciano (1860) by Bardotti. They depict The Trial of the Saints on the left, and Martyrdom of the Saints, on the right. The first chapel on the left has a Crucifixion with St Pellegrino by Sabbadini.
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.