Zelená Hora ('Green Mountain') is a castle on the north side of Nepomuk. The church has been a pilgrimage site since the 1700s. There was originally a fortified church built in the late 14th century. It was forfified probably in 1419-1420 during Hussite Wars.
The current castle was built in 1669-1696 by Šternberk family in Baroque style. In 1819 Václav Hanka's forged medieval Manuscript of Zelená Hora, a counterpart to his Manuscript of Dvůr Kralové, was allegedly discovered in the castle and not exposed as a literary hoax, by Atheneum, until 1886.
Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.