Donegal Castle was the stronghold of the O'Donnell clan, Lords of Tír Conaill and one of the most powerful Gaelic families in Ireland from the 5th to the 16th centuries. For most of the last two centuries, the majority of the buildings lay in ruins but the castle was almost fully restored in the early 1990s. It is now open to the public.
The castle consists of a 15th-century rectangular keep with a later Jacobean style wing. There is a small gatehouse at its entrance mirroring the design of the keep. The complex is sited on a bend in the River Eske, near the mouth of Donegal Bay, and is surrounded by a 17th-century boundary wall. Most of the stonework was constructed from locally sourced limestone with some sandstone.
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.