The Louvre began not as a museum but as a fortress, its medieval moat and keep still standing in the basement beneath the crowds. Kings enlarged it wing by wing across nearly seven centuries, turning a defensive castle into a sprawling royal palace, until the Revolution flung its doors open in 1793 and made the nation's treasures public. Today it holds tens of thousands of works across former throne rooms and courtyards, from Egyptian mummies to Renaissance masters. I.M. Pei's glass pyramid, once bitterly opposed, now marks its heart.
You enter through that pyramid into a light-filled hall, then choose a direction and lose track of time. Corridors run for miles; a single day barely scratches one wing. Most visitors funnel toward a small, guarded painting behind glass, where a scrum of raised phones surrounds the Mona Lisa. But the Louvre rewards wandering — a near-empty gallery of Mesopotamian carvings, the Winged Victory poised on her staircase, sunlight falling across marble. It remains a working palace of art, endlessly full, never finished.