Frogner Church was designed by the architect Ivar Næss (1878–1936) and built in 1907. The Church's main facade is made of granite, while the secondary facades against courtyards are made of brick. The church is integrated into a row of houses and apartment buildings.
A chapel associated with the church was built in 1937–39 by the architect Johan Meyer. The Gimlehøyden district surrounding the church was built in the years 1916–1925 and designed by architects Harald Hals, Harald Aars and Lorentz Harboe Ree.
References: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.