The main sight in Őriszentpéter is the Romanesque memorial church, built around 1230, then expanded in the 14th-15th century in Gothic style and converted into a fortress about 1550. The western portal is worthy of attention. The mediaeval church was decorated with frescoes, not only inside, but also outside. Most of them have been destroyed, just a few fragments have survived on the south outer wall. In the 17th century, quotations from the Bible were painted on the wall in the nave and the sanctuary, and these can still be seen today. The interior furnishings were produced to designs by church artist János Klonfár. A picture of St. Peter (Márton Michl,1801) is hung in the sanctuary. The church was last renovated in 2001.
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.