Daugavgrīva Castle was originally a monastery converted as a fortress by Swedish in the 17th century. Today there are no remnants of the medieval castle above the soil.
In 1208 there was a Dünaburg castle built by the Teutonic Knights which initially served as a monastery. The Swedish fortress of Dünamünde, designed in a Dutch style by General Rothenburg in 1641, replaced the ruined Daugavgrīva Castle by 1680. In 1695 the Commandant was captain Heinrich Nicolaus Rüdinger, forefather of future Patriarch Alexy II of Russia. Rüdinger was knighted by Charles XI of Sweden. Joachim Cronman later became the Commandant and he died on March 5, 1703.
After the fortress was seized by the Russians they reconstructed it. Regent Anna Leopoldovna of Russia, her husband Anthony Ulrich, and her son Ivan VI were incarcerated in Dünamünde in 1742. A local Lutheran church was rebuilt into the Orthodox Church of the Saviour's Transfiguration in 1775. The Russian government renamed the fortress, where only Russian soldiers were living, to Ust-Dvinsk in 1893. They had its fortifications completely reconstructed prior to World War I. During the war Ust-Dvinsk was bombarded by the Schütte-Lanz Airship SL 7 of the German Army. After the fortress was taken by Imperial Germany, it was inspected by Emperor Wilhelm II in 1917. The Latvian government, however, demolished much of the fortifications several years later. During the Cold War Ust-Dvinsk was a base for Soviet troops. The site is now known in Latvian as Daugavgrīva. There is a functional lighthouse at Daugavgrīva which was originally built in 1818. It was rebuilt in 1863, 1920, and after World War II.
Nowadays entrance in the area of castle goes along the northeastern corner. Still there is partly visible the old road which was leading from northeastern tower around the forepart of the castle up to the southeastern corner.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.