The Ulvila Church, dedicated to St. Olaf, is one of the most significant medieval buildings in Finland. The first church was built probably in 13th century to Liikistö, which was a local trade centre. According old documents the graveyard around the church was consecrated in 1347 and church was burnt badly in 1429. Historians believe that the present stone church was built after that between 1495-1510.
There are several medieval and newer artefacts inside the church, for example crucifix and statue of St. Olaf from the 1430s and communion cup from the end of Middle Ages.
The Church has been renovated several times. During the latest renovation in 2005 archaeologists found the biggest medieval coin treasure in Finland. It was buried near the sacristy stone wall in 1390s and included 1476 silver coins.
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.