Ivano castle history dates probably to the late 6th century AD, when Longobards built a fortifications against Franks and Alemans. Later it was extended agains Hungarian invasions. The first recorded document about the castle dates back to 1187 and there is a mention of the Lord of Ivano.
The Castle displays a mixture of architectural styles: the medieval walls, the Renaissance residence and the Benedictine lodge. From the watch tower you come to a moat and a large gate, followed by the outer courtyard with a fountain and an historical acacia tree from the 16th century. Next are the large hall of the old barn and the 17th century chapel. As you go on, you reach the inner courtyard, with two buildings linked by galleries.
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.