23/06/2026
In 1984, workers digging foundations for I.M. Pei's glass pyramid hit something unexpected: the walls of a medieval fortress that had been buried for 400 years.
King Philippe Auguste built the Louvre in 1190. Not as a palace. Not as a museum. As a military stronghold, designed to defend Paris from the west — specifically from English forces pressing in from Normandy. It was a square fortress roughly 256 feet (78 meters) by 236 feet (72 meters), ringed by ten towers and a water-filled moat. At its center stood the Grosse Tour (Big Tower), a circular keep nearly 100 feet (30 meters) tall with walls 14 feet (4.25 meters) thick at the base.
For three centuries, the Grosse Tour held the royal treasury, the archives, and the arsenal. In 1527, François I had it demolished. He wanted more light, more space, a Renaissance palace instead of a dark fortress. Workers tore it down to ground level — and then stopped. Nobody bothered to dig out the foundations.
The walls beneath the courtyard stayed there, untouched, for another 450 years.
The excavations ran from 1984 to 1985. Archaeologists uncovered the fortress foundations, the base of the Grosse Tour, sections of the original moats, pottery, weapons, and a parade helmet decorated with fleur-de-lis, identified as belonging to Charles VI, found shattered in pieces at the bottom of the keep well.
Today, visitors can walk directly through the former moats, circling the base of a tower that was demolished before Shakespeare wrote a single play. The medieval section sits in the Sully wing, beneath the same courtyard where the pyramid now stands.
This image is AI-generated. It imagines what it might look like to see the fortress ruins and the pyramid together from above. That vantage point does not exist. The ruins are underground, accessed by staircase inside the museum.
Have you visited the medieval section?