Musee du Louvre, Paris

Only a few people know that the third largest museum worldwide used to be the main residence of French kings and emperors for six centuries. The Old Fortress was erected in 1190 under the reign of King Philippe Auguste to protect the kingdom from the invasion of northern tribes (the Vikings). During the 14th Century, the palace was extended under Charles V and became from time to time a royal residence. The greatest changes in the original palace were made under King François I. The medieval Grosse Tour was destroyed and replaced by a sumptuous palace, still considered a masterpiece of Renaissance architecture. In 1594, Henri IV decided to build a passage between the Tuileries Palace and Louvre Palace, still known as the "Great Gallery." The "Cour Carree" was part of a vast program conducted under Louis XIII and Louis XIV to embellish the king's residence and is a symbol of the classical period. After Louis XIV moved to Versailles , the Louvre knew a static period. The most recent construction is the Glass Pyramid erected by Leoh Ming Pei under French President Mitterrand, which is now the main entrance to the museum. With 35,000 pieces and a surface of about 68,746 square meters, the Louvre cannot be taken in in one day.