Kloster Vinnenberg was established probably in the 13th century by Cistercian monks. The abbey was dissolved in 1810 post secularization. The Lage Gothic abbey church has marvelous architecture and is one of the most significant buildings in the complex. The abbey is home to a statue that is believed to be carved out miraculously from a tree trunk; it depicts Mother of the Lord and St. John. One of the oldest places for pilgrimage, the church is utilized as a conference and retreat center.
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.