The Knighthood Building was built by von Dellingshausen at the end of the 18th Century and today, it accommodates the County Government of Saaremaa. At the beginning of the 19th Century, the house belonged to the Nobility of Saaremaa, then in 1912, to the Noblemen's club. The County Government of Saaremaa bought the house in 1920. The foundation of the building is symmetrical, with a high socle floor. The façade is proportionately divided by three protuberances, the central of which is crowned by a bow-shaped pediment. The balcony with dolomite marble columns and an iron balustrade decorates the façade.
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.