The oldest parts of Alva Church are the choir and the apse, dating from the early 13th century. To this the nave was added during the late part of the same century. Construction of the broad tower started about a hundred years later but was never finished; hence the somewhat squat appearance of the church today. It seems in fact that construction of the church came to a rapid end: apart from the half-finished tower, the main southern portal also seems to have been finished in a haphazard, chaotic way.
The choir portal is Romanesque in style and carried some sculpted reliefs, possibly executed by the locally active Master Sigraf. The likewise Romanesque northern portal of the church is also decorated with sculptures.
Inside, the church displays a set of frescos carried out at the end of the Middle Ages, probably just before the reformation and possibly by the same artist who decorated Lau Church. Among the furnishings, the dominating triumphal cross, dating from the middle of the 13th century, and a partly preserved baptismal font, executed by the Romanesque master carver Hegvald sometime during the end of the 12th century, are especially notable. The pulpit dates from 1740 and the unusually decorated altarpiece from 1653. The church was renovated in 1953-54.
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.