Raschpëtzer is an artifical aqueduct (qanat) from Roman times, consisting of about 35 wells dug into the rock and linked together by a 600 m main passage and a net of secondary passages, designed to capture the underground water and take it to Roman villas.
Raschpëtzer is a particularly well preserved example of a qanat and is probably the most extensive system of its kind north of the Alps. It has been under systematic excavation for the past 40 years. It was built during the Gallo-Roman period, probably around the year 150 and functioned for about 120 years thereafter.
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.