Alt-Regensberg Castle was built about the mid-11th century AD by the House of Regensberg in the municipality of Regensdorf. The decline in importance of the castle had been shown already in the Old Zürich War, when Zürich's opponent Alt-Regensberg occupied without resistance. Later the ruins served as a quarry.
The quadratic keep dates from the first construction phase. The exterior of the residential tower has been transformed remarkably over the years. The outer casing of the 11th-century structure was filled with boll stones and mounted in horizontal mortar joints strokes. By 1200 the entire outer surface was chipped away and replaced with carefully edited boss squares. The whole tower thus received a much more upmarket appearance.
In the northern part of the complex is a rectangular foundation wall leaning against the perimeter wall. Here arose in the 12th or early 13th century wooden buildings that served as stables and outbuildings. They were moved to the south and replaced by a palas in the course of the 14th century claimed the whole area between keep and circular wall in the northeastern area.References:
Hluboká Castle (Schloss Frauenberg) is considered one of the most beautiful castles in the Czech Republic. In the second half of the 13th century, a Gothic castle was built at the site. During its history, the castle was rebuilt several times. It was first expanded during the Renaissance period, then rebuilt into a Baroque castle at the order of Adam Franz von Schwarzenberg in the beginning of the 18th century. It reached its current appearance during the 19th century, when Johann Adolf II von Schwarzenberg ordered the reconstruction of the castle in the romantic style of England's Windsor Castle.
The Schwarzenbergs lived in Hluboká until the end of 1939, when the last owner (Adolph Schwarzenberg) emigrated overseas to escape from the Nazis. The Schwarzenbergs lost all of their Czech property through a special legislative Act, the Lex Schwarzenberg, in 1947.
The original royal castle of Přemysl Otakar II from the second half of the 13th century was rebuilt at the end of the 16th century by the Lords of Hradec. It received its present appearance under Count Jan Adam of Schwarzenberg. According to the English Windsor example, architects Franz Beer and F. Deworetzky built a Romantic Neo-Gothic chateau, surrounded by a 1.9 square kilometres English park here in the years 1841 to 1871. In 1940, the castle was seized from the last owner, Adolph Schwarzenberg by the Gestapo and confiscated by the government of Czechoslovakia after the end of World War II. The castle is open to public. There is a winter garden and riding-hall where the Southern Bohemian gallery exhibitions have been housed since 1956.