Cahokia Mounds is the largest pre-Columbian settlement north of Mexico. It was occupied primarily during the Mississippian period (800–1400), when it covered nearly 1,600 ha and included some 120 mounds. It is a striking example of a complex chiefdom society, with many satellite mound centres and numerous outlying hamlets and villages. This agricultural society may have had a population of 10–20,000 at its peak between 1050 and 1150. Primary features at the site include Monks Mound, the largest prehistoric earthwork in the Americas, covering over 5 ha and standing 30 m high.
Cahokia Mounds State Historic Site includes 51 platform, ridgetop, and conical mounds; residential, public, and specialized activity areas; and a section of reconstructed palisade, all of which together defined the limits and internal symmetry of the settlement. Dominating the community was Monks Mound, the largest prehistoric earthen structure in the New World. Constructed in fourteen stages, it covers six hectares and rises in four terraces to a height of 30 meters. The mounds served variously as construction foundations for public buildings and as funerary tumuli. There was also an astronomical observatory, consisting of a circle of wooden posts. Extensive professional excavations have produced evidence of construction methods and the social activities of which the structures are further testimony.
Cahokia Mounds is a National Historic Landmark and a designated site for state protection. It is also one of only 23 UNESCO World Heritage Sites within the United States.
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.