The Alatskivi Manor (Allatskiwwi in German) was first mentioned in 1601. In 1628 Swedish king Gustav Adolf II donated it as a gift to his secretary Johan Adler Salviusele. In 1642 the manor was further passed into the possession of Hans Dettermann Cronmann and in 1753 it was bought by Otto Heinrich von Stackelberg.
The present huge castle manor was designed by the land owner Arved von Nolcken. He had travelled in Scotland and fascinated to the Balmoral Castle. Von Nolcken wanted to build a copy of royal castle to Alatskivi. The new neo-Gothic main building was completed in 1885 and it was one of the most luxurious manor houses in Estonia.
At present, the building is owned by Alatskivi Community and being restored to serve as a museum and restaurant.
Reference: Visit Tartu
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.