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.
Kakesbeck is one of the largest medieval fortifications in Münsterland and the oldest castle in Lüdinghausen. The imposingly grown complex originated in 1120 as a motte, a small hilltop tower castle. After numerous changes of ownership, the castle was extended onto two islands, but it was not until the 14th century that it underwent significant alterations and extensions under the von Oer family. The estate experienced its heyday in the middle of the 18th century, when it covered an area of almost one square kilometre and consisted of five further outer castles in addition to the core castle, which were secured by ramparts and moats.
The well-maintained condition of the castle today is thanks to the late Wilfried Grewing, the former lord of the castle. The foundation named after him has been particularly committed to preserving the property since 2020.