French President Emmanuel Macron compared the facelift to the rebuilding of the Notre Dame cathedral, which is still ongoing six years later.

Last spring, the world’s most-visited art museum, the Louvre in Paris, proposed moving its most popular artwork—Leonardo da Vinci’s Mona Lisa—to its own subterranean room. Now, that idea is becoming reality.

The iconic Louvre in Paris is no stranger to crowds. Since first opening in 1793, the museum has played host to millions of guests and undergone dozens of expansions and renovations to accommodate them. Today, though, overtourism has brought the historic site to a breaking point.