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 Pilgrimage Church of Wies (Wieskirche) is an oval rococo church, designed in the late 1740s by Dominikus Zimmermann. It is located in the foothills of the Alps in the municipality of Steingaden.
The sanctuary of Wies is a pilgrimage church extraordinarily well-preserved in the beautiful setting of an Alpine valley, and is a perfect masterpiece of Rococo art and creative genius, as well as an exceptional testimony to a civilization that has disappeared.
The hamlet of Wies, in 1738, is said to have been the setting of a miracle in which tears were seen on a simple wooden figure of Christ mounted on a column that was no longer venerated by the Premonstratensian monks of the Abbey. A wooden chapel constructed in the fields housed the miraculous statue for some time. However, pilgrims from Germany, Austria, Bohemia, and even Italy became so numerous that the Abbot of the Premonstratensians of Steingaden decided to construct a splendid sanctuary.