The Holy chamber of Oviedo (Cámara Santa de Oviedo) is a pre-Romanesque church built next to pre-romanesque Tower of San Miguel of the city's cathedral. Nowadays, the church occupies the angle between the south arm of the cathedral transept and a side of the cloister.
It was built during the 9th century as a palace chapel for King Alfonso II of Asturias and the church of San Salvador of Oviedo. Apart from acting as royal chapel, the Holy Chamber was built to house the jewels and relics of the cathedral of San Salvador in Oviedo, a function it continues to have 1200 years later. Some of these jewels were donated by the Kings Alfonso II and Alfonso III, and represent extraordinary gold artifacts of Asturian Pre-Romanesque, brought from Toledo after the fall of the Visigothic kingdom.
Consequently, the cathedral of Oviedo was also called Sancta Ovetensis; owing to quantity and quality of relics contained in the Cámara Santa. The Holy Chamber remains as the only sample of the early medieval complex. It was built as a relics' room to keep the different treasures associated with the Kingdom of Asturias (Cross of the Angels, Victory Cross, Agate box, Arca Santa and Sudarium of Oviedo), brought from Jerusalem to Africa, and after several translations was finally deposited at Oviedo by Alfonso II of Asturias.
It was declared a World Heritage Site by UNESCO in December 1998.
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.