The St.Caherine's Church of Muhu is considered one of the most remarkable early-Gothic buildings in Estonia. It was first mentioned in Hermann von Wartberge's Chronicle dated 1276. The exterior architecture of the Muhu Church is a strict monumental style and its originality is prominent. The Muhu Church has preserved its original shape. Around 1663, a little wooden steeple was added to the church, but perished together with the roof in 1941. In 1993, during the restoration period an additional roof was constructed on the facade of the church to protect the church bell.
As for the interior furnishings of the Muhu Church one will find an altar table made of dolomite, which has been preserved from the time of its original construction. Also the stone base of the baptismal basin originates from the Middle Ages.
The pulpit is in Renaissance style and was completed on 1627. It is one of the oldest in Saaremaa and was made by Balthasar Raschky. The Classicist altar was created by Nommen Lorentzen in 1827. The altar painting has survived from the original altar and the painting was finished in 1788.
In the Muhu Church and churchyard there are worth noting the trapezium-shaped tombstones with pagan symbols found only on the islands and Western Estonia. They have been traced to the 12th and 13th centuries. The most intricate tombstone is presently located in the frame of the door leading to the wall staircase. It is one of the two preserved in Estonia from the 12th-13-th centuries depicting human figures. Through discovering tombstones, bones and some other rare archaelogical finds, the church is thought to have been erected on a sacred site of the ancient Muhu inhabitants.
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.