The Louvre

It began around 1190 as Philip Augustus's fortress, whose foundations can be seen in the basement, and was a royal palace until Louis XIV moved to Versailles. It opened as a museum in 1793, during the Revolution, and I. M. Pei's glass pyramid dates from 1989.

It shows some 35,000 works in three wings, from Egyptian antiquities to 19th-century European painting. Beyond the Mona Lisa, the Venus de Milo and the Winged Victory of Samothrace, look for Napoleon III's apartments and Delacroix's Liberty Leading the People.