Klopp Castle is the landmark of Bingen. It stands on a hill above the town with a wide-ranging view, which may have been the site of a Roman fortification built by Drusus at Bingium around 10 CE. The hill is one of three locations where local legend says that Emperor Henry IV was imprisoned by his son in 1105 or 1106, this being the first surviving mention of a castle there.
The last medieval castle on the site was built in the 13th century: possibly around 1281, possibly between 1240, when Kloppberg (Klopp Hill) is mentioned as the residence of a churchman, and 1277, the first mention of Burg Clopp. Together with Ehrenfels Castle on the opposite side of the Rhine and later the Mouse Tower, it enabled the Archbishopric of Mainz to exact tolls on river trade. In 1438 the archbishop sold the town and the castle to the cathedral chapter and the townspeople effectively controlled it. The castle was already decaying in the 16th century and was destroyed in the Thirty Years' War, but was rebuilt in 1653. The French destroyed it again in 1689 in the War of the Palatine Succession, and in the final phase of the War of the Spanish Succession in 1713, the Mainz forces themselves blew up what was left to prevent its use by the enemy. Early 19th-century paintings show ruined walls, one connecting the castle to the town, but the castle itself levelled.
The state of Hesse acquired the ruin in 1815 and sold it to Hermann Faber, a lawyer. It was later owned by a Berliner called Rosenthal, who renovated the well. Both charged tourists to climb the gate tower as a viewing platform; Faber built a stairway up the outside of the walls and a viewing room at the top which he furnished with books of poetry, a comfortable sofa and a fully equipped writing desk, and laid out the grounds as a garden with romantic paths through the grapevines, trees and flowers. He also installed an aeolian harp. The castle was one of the major sights of the Romantic Rhine. J.M.W. Turner sketched a view of it from the River Nahe in 1844. By the end of the 19th century, some 75,000 entries had been made in the visitors' book.
In 1853 the gatehouse, the bridge across the moat and the fortifications were rebuilt for Ludwig Maria Cron. The bergfried was rebuilt as a crenellated tower 26 metres high, with four corner turrets. In 1875–79, a new Gothic building was built on the site. The architect for both was the mayor, Eberhard Soherr. The base of the bergfried, the moat and parts of the southern curtain wall and its chemin de ronde are the only remnants of the medieval castle.
The rebuilt bergfried formerly housed the town's local history museum, which moved in 1998 to a former power station on the waterfront. The larger Gothic building has been the seat of government and mayoral residence since 1897. There is also a gourmet restaurant.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.