The Bergkirche was built in the early 18th century by Prince Paul Esterházy. Eisenstadt was the seat of the Esterházy family, and the church lies just short walk to the west of the family's main palace.
The Bergkirche is architecturally quite unusual and is built in two parts. The main section, the church proper, is approximately a square. The interior is in Baroque style. The ceiling takes the form of a dome, which was painted in fresco in the late 18th century.
A side chapel is dominated by a large marble sarcophagus, the tomb of the composer Joseph Haydn, who spent much of his career in Eisenstadt working for the Esterházys. The remains of most of Haydn's body have rested here since 1932; the skull was added (with due pomp and ceremony) only in 1954; for the reason for the disparity see Haydn's head.
The church still possesses its original organ, built in the 18th century by the Viennese maker Gottfried Malleck; the instrument has been restored to its original state, as it was when it was played by Haydn and Beethoven at the premieres of famous works. The original console, however, is no longer used but resides now in the nearby Haydn Museum.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.