Pont Neuf begins disappearing under JR’s temporary artificial cave

The Pont Neuf, Paris’s oldest bridge, has begun to disappear beneath a monumental artificial cave, a temporary public artwork that transformed the 17th-century landmark this week. The inflation of the massive, rocky-looking structure over the historic span marks the dramatic culmination of a project more than a year in the making.

The installation, titled "La Caverne du Pont Neuf," is the work of French artist JR. Funded by the sale of his work and corporate partners, it is one of the most ambitious public artworks Paris has seen in decades. The inflation process was conducted overnight after a weather delay, making the 400-year-old bridge appear as though a prehistoric cliff had risen from the Seine.

From the outside, the installation resembles a rocky mass that breaks the landscape, according to the artist. It measures 120 meters long and 18 meters tall, yet is constructed almost entirely from air, utilizing 80 fabric arches filled with 20,000 cubic meters of it. The entire structure weighs only about five tons. The fabric was hand-stitched by 25 artisans in Brittany, and the design ensures nothing digs into the historic stonework. Engineers spent weeks rehearsing a controlled...