The Santa María la Real de la Oliva is a Cistercian monastery in Carcastillo, Navarre. It was established in the 12th century. Present buildings date from 13th - 15th centuries.
Construction at the site is attributed first in 1134 to King García Ramírez of Navarre, known as the restorer. This king died in 1150 and the same year the abbey was founded, or refounded, as a daughter house of the Morimond and Escaladieu Abbeys.
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.