All Saints (Alla Helgona) Church was built in the late 1200s, but during the Duke Karl's time (1590-1618) it went through a radical transformation. At the restoration in 1909 the church received its small ridge turrets, which is a replica of the tower on Erik Dahlberg´s engravings of Nyköping. In 1665 the church was ravaged by fire. At the recent restoration in 1959-1960 were the pillars restored in to original condition, limestone from the island of Öland.
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.