The east wing of Gram Castle was built in the beginning of the 16th century. The builder is unknown, but was probably one of the Reventlow family, who owned Gram from about the middle of the 15th century until 1560. The south wing was built by the Commander Hans Schack (1609 - 1676) a few years after he bought the manor in 1664. The west wing of the manor was built 1752 by Countess Anna Sophie Schack (1689 - 1760). Today it is a conference center.
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.