The Torre del Fraile is one of a set of military watchtowers built around the South and East coast of Spain to keep an eye on passing shipping and Barbary pirates. The watchtowers were in sight of one another and it was therefore possible to get a signal to Gibraltar from the watchtower in Tarifa. The tower was designed by Luis Bravo and Juan Pedro Laguna in 1588.
The tower is about 240 metres back from the sea and Cala Arenas and 120 metres above it. The tower is over six metres in diameter and was over thirteen metres high until the top collapsed in 2006 with the loss of a window and the upper staircase. The tower's entrance was over five metres in the air and this led onto a floor. From this the soldiers could climb to the top where space was reserved for firewood for signalling.
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.