The cryptoporticus (covered corridor or passageway) of Arles, dating from the 1st century BC was built as foundation for the forum, which has since been replaced by the Chapel of the Jesuit College and the City Hall. Three double, parallel tunnels arranged in the form of a U are supported by fifty piers. Masons' marks on the stonework indicate that it was built by Greeks, probably from Marseille. Similar structures in Narbonne, Reims, and Bavay were used as granaries. The cryptoporticus at Arles is, however, too damp for prolonged storage and may have served as a barracks for public slaves. The cryptoporticus of Arles is listed as a UNESCO World Heritage Site, together with other Roman buildings of the city, as part of the Arles, Roman and Romanesque Monuments group.
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.