The first Christian church was probably a wooden church. Of this church there is no trace, but the baptismal font in the Church today has probably belonged to this church. In the 1220s a new stone church of considerable size was built in round-headed Romanesque style and consisted of a nave with four pillars, chancel with two cross-arms and apse, an extension in the rear of the chancel where the altar was placed. A large tower in the west would be part of the building, but it never came to execution. The nave is left intact to this day. Lau church is the island’s largest country church. It is famous for its unique acoustics.
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.