Venø Church's age is difficult to date but it was probably built around the time of the Reformation (1536), making it the oldest building on the island. According to tradition, it is the smallest church in Denmark measuring only 9.8 by 4.2 meters. The low ceiling and the limited seating capacity (only about 50 places) reinforce this impression. The church is built of fieldstone while brick has been used for the corners and later extensions. There is no tower as the church bell is inside the gable at the west end of the church.
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.