Šamorín Gothic church is composed of three naves. The eastern part of the church, an early Gothic holy cave, was constructed in the first half of the thirteenth century. Its outer walls bear traces of the late reconstruction. This, and the supporting pillars, may have been the work of Bratislava's mayor Alexander’s son Karol shortly after 1287. The holy cave was lit by five arched windows. Among these, only three east side windows are original, made in the first half of the 13th century. The two remaining windows on the south side were refurbished in the Gothic style in the 15th century, then in the Baroque style in the 18th century and, finally, enlarged in 1931.
After reconstruction around 1290, the whole church was decorated with painted figures, which were later covered but were revealed again during restoration. There are also paintings of standing Saints, a depiction of Holy Mary's death and Judging Jesus. The north side wing was built/rebuilt later, probably after some kind of a disaster, fire or possibly flood.
The organ case dates from the second half of the 19th century. The wooden gate on the outside of the north hall was made in 1844; the altar was made of red marble in 1904.
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.