Underneath the Palais de Tokyo art center is one of the best-kept secrets of street art in Paris. The center started the Lasco project in 2012 to showcase urban art in the building’s subterranean passages, corridors, and stairways—a part of the center until then undisclosed to the public.

The Lasco project is an underground wonderland of murals and art pieces by some of the most renowned street artists from around the world. The dark corridors are filled with a diverse mix of graffiti and art pieces, giving off a mysterious and secretive vibe that feels like you’re entering a concealed universe in the shape of a street art maze.

New artists are invited every year to fill the falls of the constantly evolving gallery, which is now accessible through a guided tour of the museum. Note that part of the Lasco project remains hidden from the public, featuring pieces by renowned photographer and street artist JR and duo Os Gemeos. The only way to see their art installation is via a video inside the Palais de Tokyo.