Château de Quillan was first mentioned in 1125. There had been a fort built by Visigoths already in 781 AD. The castle was conquered by the Royal army of France in 1210 during the Albigensian Crusades. The castle got its current appearance in restorations of 1232 and 1341. Since then Quillan castle has been damaged in wars by Spanish Armies and Huguenots (1575).
Since the 18th century Château de Quillan was left to decay and dismantled. Today still the impressive ruins remain overlooking the village.
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.