Schloss Solitude was built as a hunting lodge between 1764 and 1769 under Duke Karl Eugen of Württemberg. Schloss Solitude was originally designed to act as a refugium, a place of quiet, reflection and solitude (thus the name). Construction of the castle was plagued by political and financial difficulties. Karl Eugen had taken Württemberg into the Seven Years' War on the losing side against Prussia. The building exceeded the budget allocated by the duchy of Württemberg. Further, political wrangling between the duke and influential Stuttgart land barons led to the duke moving temporarily from Stuttgart to Ludwigsburg. In the long run, the castle was prohibitively expensive to keep just as a temporary residence. In 1770 it housed a high school founded by Duke Eugen. In 1775, the Karlsschule academy moved to Castle Solitude. It served as an academy of arts, a military academy, and later a general university for children of the elite. Eventually, maintenance costs led to its closure as a school after the Duke's death late in the 18th century. Between 1972 and 1983, the Federal Republic of Germany restored the castle.
Since 1990, the annexed buildings (Officen-building and Kavaliers-building) have housed the Akademie Schloss Solitude. The Kavaliers building incorporates living quarters for students.
Castle Solitude was designed by a working group at the ducal court under the guidance of Philippe de La Guêpière with active input from Duke Karl Eugen and master craftsmen. Its exterior is typical Rococo. On the inside, however, the style is characteristic of classicism: instead of the irregular lively forms typical of Rococo, the proportions of the rooms and wall are typically classical in design.References:
Ängsö Castle was first named as "Engsev" in a royal charter by king Canute I of Sweden (r. 1167-1196), in which he stated that he had inherited the property after his father Eric IX of Sweden. Until 1272, it was owned by the Riseberga Abbey, and then taken over by Gregers Birgersson.
From 1475 until 1710, it was owned by the Sparre family. The current castle was built as a fortress by riksråd Bengt Fadersson Sparre in the 1480s. In 1522, Ängsö Castle was taken after a siege by king Gustav Vasa, since its owner, Fadersson's son Knut Bengtsson, sided with Christian II of Denmark. However, in 1538 it was given by the king to Bengtsson's daughter Hillevi Knutsdotter, who was married to Arvid Trolle.
In 1710, the castle was taken over by Carl Piper and Christina Piper. Ängsö Castle was owned by the Piper family from 1710 until 1971, and is now owned by the Westmanna foundation. The castle building itself was made into a museum in 1959 and was made a listed building in 1965. It is currently opened to visitors during the summers.
The castle is a cubical building in four stores made by stone and bricks. The lower parts is preserved from the middle ages. It was redecorated and expanded in the 1630s. The 4th storey as well as the roof is from the expansion of Carl Hårleman from 1740-41. It gained its current appearance in the 1740s.