St. Donat Zadar

The pre-Romanesque church of St.Donat Zadar (built in the 9th century) is the only monumental rotonda from early medieval Dalmatian architecture, and bears a similarity only to the chapel at the court of King Karl the Great in Aachen.
The St. Donat church hasn't been used for religious purposes for a long time, but it is often used for musical performances because of excellent acoustic characteristics.
When Pope John Paul II, in May 2003, visited Zadar, he held a mass in front of St. Donat Church.