In the outskirts of Mtskheta are the ruins of Armaztsikhe fortress (3rd century BC). Armaztsikhe was the residence of the Kings of Iberia. This is one of the oldest cities of the Antique Era, which is not fully explored yet. It is also called like Georgian Acropolis. The Greek historian Dio Cassius mentioned this place in his book “The history of Rome”. He wrote that in 65 years BC, Roman Senator Gnaeus Pompeius invaded Iberia and reached this Acropolis too.
Archaeological investigations began in 1943 and three main cultures were identified: the oldest finds were dated to the 1st century BC to 2nd century AD, the central findings on the 3rd-5th centuries, and the latest to the 6th century. Consequently Armaztsikhe was destroyed by the Arabs in the 8th century. There are a royal sarcophagus, vestiges of the ramparts, a fortified tower and supporting pillars, foundation walls of the palace, a bath house, a wine cellar, a pre-Christian temple and a canal system.
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.