Harry Avery's Castle is situated half a mile south-west of Newtownstewart, Northern Ireland. It is a rare example of a stone castle built by a Gaelic Irish chief, although its origins and history are uncertain. It is associated with and named after Henry Aimhréidh O'Neill (died 1392), whose name was anglicised as Harry Avery.
The standing part of the castle comprises a two-storey rectangular construction fronted by massive D-shaped twin towers. Although having the appearance of a gatehouse, this structure was in fact a simple tower house with the D-towers added to the front. The tower comprised a vaulted basement entered from a large door between the D-towers. Above this was a hall on the first floor level, which was accessed from the courtyard. The southerly D-tower contained a spiral stair linking the two storeys, and both D-towers contained small rooms at first floor, with single windows in their round walls. Traces of a mural stair lead up from the first floor, and there is a latrine chute leading up, suggesting at least a parapet at the second floor. Examination of the structure suggests that it was built in a single phase, rather than being a modification of an older gatehouse.
The design of the castle has been compared to that of Elagh Castle, Inishowen, which also appears to have been a native-built castle featuring D-towers. The inspiration is thought have come from Norman castles such as Carrickfergus Castle and Castle Roche, both of which have true gatehouses flanked by D-towers. The overall design of Harry Avery's Castle is also similar to other Gaelic fortresses such as Seafin, County Down, which were later enclosed by a curtain wall with a tower house.
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.