Celles-sur-Belle royal abbey was founded in 1137. It was rebuilt in the 15th century and destroyed by Huguenots in 1568. The current abbey was reconstructed between 1660 and 1685 on the orders of Louis XIV.
Overlooking both the Belle Valley and beautiful French-style gardens, the majestic 17th-century convent buildings in the Louis XIV style house a museum where you can see the Abbot's room, a recreated monk's cell, and collections of religious objects and ecclesiastical clothing.
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.