Lohja church is the third biggest medieval church in Finland. It dates back to the 15th century, probably between years 1470 and 1490. Impressive chalk paintings inside the church are made in the regime of bishop Arvid Kurki (1510-1522).
The Lohja parish was established in 1230s or 1240s and there have been several wooden churches before the present one. Also origins of the bell tower date back to the Middle Ages. The upper part was added in 1740.
The church site is named as the national built heritage by National Board of Antiques.
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.