The Roman Amphitheater in Trier is designated as part of the Roman Monuments, Cathedral of St. Peter and Church of Our Lady in Trier UNESCO World Heritage Site. The arena, built in the 2nd century A.D. for cruel games with gladiators and animals, had a seating capacity of about 20,000. When you enter the premises you walk through the ruins of the entrance gate. This was used as a quarry in the Middle Ages. The arena itself is surrounded by a protecting wall with openings for animal cages. Underneath the arena is a vast cellar where, in Roman times, prisoners sentenced to death were kept alongside exotic wild animals like African lions or Asian tigers.
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.