The Tumulus of St. Michel is a megalithic grave mound, located east of Carnac. The 125m long, 60m wide and 10m high mound is the largest grave mound in continental Europe. The age of the monument, and the chronology of the construction of the central burial-chambers and outlying dolmen have been the subject of much speculation. Ancient samples were radiocarbon dated, but the results were too disparate to be significant. Recent excavations point to this large tumulus being constructed in several stages but in a rather short lapse of time, around the middle of the 5th millennium B.C. Today there is a chapel built on top of it.
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.