Louvre Museum

The glass pyramid rising from the courtyard of the Louvre serves as the primary entrance to what was once a defensive fortress. King Philippe Auguste built the original stone keep here in the late twelfth century to protect Paris from invaders. Four hundred years later, François the First demolished those medieval walls to begin a royal palace. When the French Revolution forced the royal family to leave, the building became a public gallery, housing art once reserved for the eyes of kings.