Bottna Church dates from the 12th century when the sea level was much higher, possibly reaching the foot of the hill on which the church stands. The church retains the character of the Middle Ages when entrances were on the southern long wall. The door was moved, but the doorway remains, where there is a carved stone relief.The walls surrounding the basilica and parts of the chancel are original. Additions were made to the chancel during the 16th or 17th centuries. The altarpiece, possibly a war trophy from Germany during the Thirty Years' War, was a gift from local man Bishop Johan Wingård. The church bell, cast in 1736, hung in a separate belfry until the present tower was built.
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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.