The Kerimäki Church is the largest wooden church in the world. Designed by Anders Fredrik Granstedt and built between 1844 and 1847, the church has a length of 45 metres (148 ft), a width of 42 m (138 ft), a height of 37 m (121 ft) and a seating capacity of more than 3,000. Altogether there can be 5,000 people at a time in the church.
It has been rumoured that the size of the church was the result of a miscalculation when it was built (supposedly the architect was working in centimetres, which the builder took to be inches, which are 2.54 times larger). Further studies, however, have shown that the church was actually intended to be as big as it is, so it could easily accommodate a half of the area's population at the same time.
During wintertime, services are held in a smaller "winter church" (built in 1953), since the main building has no heating.
Reference: Wikipedia
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.