The Old Louvre occupies the site of the 12th-century fortress of King Philip Augustus, also called the Louvre. Its foundations are viewable in the basement level as the “Medieval Louvre” department. This structure was razed in 1546 by King Francis I in favor of a larger royal residence which was added to by almost every subsequent French monarch. King Louis XIV, who resided at the Louvre until his departure for Versailles in 1678, completed the Cour Carrée, which was closed off on the city side by a colonnade. The Old Louvre is a quadrilateral approximately 160 meters on a side consisting of 8 ailes (wings) which are articulated by 8 pavillons (pavilions). Starting at the northwest corner and moving clockwise, the pavillons consist of the following: Pavillon de Beauvais, Pavillion de Marengo, Northeast Pavilion, Central Pavilion, Southeast Pavilion, Pavillon des Arts, Pavillon du Roi, and Pavillon Sully (formerly, Pavillon de l’Horloge). Between the Pavillon du Roi and the Pavillon Sully is the Aile Lescot (“Lescot Wing”): built between 1546 and 1551, it is the oldest part of the visible external elevations and was important in setting the mold for later French architectural classicism. Between the Pavillon Sully and the Pavillon de Beauvais is the Aile Lemercier (“Lemercier Wing”): built in 1639 by Louis XIII and Richelieu, it is a symmetrical extension of Lescot’s wing in the same Renaissance style. With it, the last external vestiges of the medieval Louvre were demolished.