Tourism in Paris due to a change of reign after every century. On March 3, 1989, I.M. Pei inaugurated the Glass Pyramid. This also serves as an official entrance to the main exhibition hall, which in turn leads to the temporary exhibition halls. The Musée is divided into 3 separate wings: Sully, Richelieu and Denon, which showcase 35,000 pieces of art, dating back to the Middle Ages. Some of the most renown pieces of art showcased at The Louvre are the Leonardo da Vinci's "Mona Lisa", Venus of Milo, Winged Victory of Samothrace, "Liberty Leading the People", and the "Dying Slave" by Michelangelo.
Paris in the Middle Ages not have an efficient system of covered sewers until Napoleon built them at the beginning of the 19th century. Street lighting was almost nonexistent in the Middle Ages. In 1318, it was recorded that there were just three street lanterns in Paris: one candle in a lantern outside the entrance to the Châtelet fortress; a candle outside the Tour de Nesle to indicate its entrance to boatmen; and a third lantern outside the Cemetery of the Innocents to remind passers-by to pray for the souls of the deceased. Very little light came from houses, since glass windows were extremely rare;