PARIS — French artist JR began inflating a giant cave installation over the Pont Neuf in Paris in May 2026, causing the city's oldest bridge to begin to vanish from view. The work, titled La Caverne du Pont Neuf, will be open to the public around the clock from June 6 through June 28, 2026.

The inflation was carried out overnight after bad weather delayed the process, marking the first major visible stage of a project that had been in development for more than a year. Since March 2026, the transformation of the Pont Neuf has been documented with time-lapse cameras, including one fixed on a rooftop terrace overlooking the Seine.

The structure spans 120 meters in length and rises 18 meters, approximately the height of a six-story building. It is built almost entirely from air, consisting of 80 fabric arches filled with 20,000 cubic meters of air, and weighs about five tons. The fabric was hand-stitched by 25 artisans in a village in Brittany.

The installation does not attach to the Pont Neuf, and no element penetrates the historic stone. Engineers rehearsed a controlled collapse in a hangar at Orly airport to ensure the structure would descend gently in the event of a power failure. After deinstallation, the fabric will be reused or recycled, and the bridge will reappear in its original appearance.

"The installation looks like a rocky mass that literally breaks the landscape," JR said. "My idea is to bring 'mineral and nature' back to the heart of the city," he added, saying that air leaves no scar. He described the work not as covering the bridge but as undressing it, sending the dressed stone back to the limestone quarries from which Paris was cut.

Visitors will be able to walk for free through a long, dark tunnel that blocks daylight and where, according to JR, people will lose track of time. He said the cave serves as a warning, referencing Plato's allegory in which prisoners mistake shadows on a wall for reality, and said that contemporary caves are phones because people believe their social media algorithms represent reality. Visitors access an augmented-reality layer built by Snap by raising their phones when entering the cave, which features a low, mineral hum composed by Thomas Bangalter, formerly of Daft Punk.

While open, the cave will close the Pont Neuf to traffic and will be visible from the quays, passing boats, and the top of the Eiffel Tower. The run will coincide with Paris Fashion Week, World Music Day, and the Nuit Blanche arts festival. The bridge has carried Parisians across the Seine for more than 400 years.

Christo and Jeanne-Claude wrapped the Pont Neuf in pale golden fabric in 1985, using 13 kilometers of rope after a decade of negotiations with city hall. That installation attracted three million visitors over two weeks. Bangalter was 10 years old when Christo wrapped the bridge in 1985. A square adjacent to the bridge now bears the names of Christo and Jeanne-Claude.