St. James' Church or Skt. Ibs Kirke is a travertine church from around 1100. In 1808 it was transformed into a field hospital for Spanish soldiers. In 1816 the church and the graveyard were sold to a local merchant and used as warehouse until 1884. The porch, tower and chancel were demolished, however, the church was restored in 1922. Today, only the aisle is left. The famous Danish painter L.A. Ring is burried in the churchyard which is still used.
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.