Hallwyl Castle is one of the most important moated castles in Switzerland. It is located on two islands in the River Aabach, just north of the northern end of Lake Hallwil. Since 1925, it has been open to the public, and since 1994 it has been owned by the canton of Aargau and is part of the museum of Aargau.
The first mention of the castle is in the year 1256. However, the originally free noble family of Hallwyl were first mentioned in a testament from 1167. Some discoveries indicate that the castle was founded in the late 12th century. Hallwyl Castle was the home castle of the Lords of Hallwyl, who owned the surrounding land and parts of the lake as their personal property. It consisted of a residential tower with a dry moat. In 1265 the keepwas expanded.
In the early 14th century the dry ditch was converted into a moat. The old castle tower was surrounded by a moat and a wall on what became the Rear Island. To the east of the Rear Island, an artificial island was built in the River Aabach. This island, the Front Island, was outfitted with a curtain wall, and was occupied by residential and commercial buildings. During the conquest of Aargau in 1415 by the Swiss Confederation, the castle (which was known after 1369 as the Ganerbenburg) was burnt by the Bernese troops. The castle was immediately rebuilt and expanded.
After the construction of two turrets in 1500 and 1579-1590 there was an extensive general renovation. After long neglect, the castle was partly rebuilt in neo-Gothic style in 1861 and 1870-74. However, this project was mostly reversed in 1914.
In 1925 the family foundation made an effort to preserve the castle. Since 1994, it has been in possession of the Canton of Aargau.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.