Thorsager round church is the only one of its kind in Jutland (and one of Denmark's seven medieval round churches). It was built of brick around 1200 and is one of Jutland's oldest brick buildings - perhaps the oldest. Its thick walls (1m) are an indication of the defensive role it played.
The church may lie on the site of a pre-Christian sacrificial place for the god Thor. The size of the church and its architecture suggeste that is was built by an important man - probably the king. During restoration work in 1877-78 most of the church's outer walls were replaced with new bricks. Original bricks can still be seen in the north wall of the choir. During the last restoration in 1950-52 the beautiful church interior was restored with amongst other things a new altar and pulpit. There is access to the upper floor by a staircase within the door of the church.
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.