Saint Peter's church in Grou was built in the first half of the 13th century out of tuffstone. Already in the 13th century the church was heightened. In the 15th century the church was lengthened to the west and heightened for the second time with brick. The current tower dates from the early 15th century. The monumental Pipe organ was built in 1853 by L. van Dam & Zn. from Leeuwarden.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.