Liechtenstein Castle is a castle near Maria Enzersdorf in Lower Austria bordering Vienna. The castle, originally built during the 12th century, was destroyed by the Ottomans in 1529 and 1683, and remained in ruins until 1884, when it was rebuilt.
Liechtenstein Castle is the origin of the name of the Liechtenstein family, the ruling house of the country of the same name, which owned the castle from at least 1140 until the 13th century and again from 1807 onwards.
Today, the castle is mainly known for the Nestroy Theatre Festival held annually during the summer months.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.