In 1985, French diver Henri Cosquer made the find of a lifetime: While exploring the deep waters off the coast of Marseille, France, he came upon an underwater cave brimming with hundreds of prehistoric rock paintings and engravings. Only accessible via a 137-yard natural tunnel, the unique cave lured other curious divers, including at least three people who died trying to explore it.
Today, however, the site—named the Cosquer Cave after its discoverer—is at risk of flooding due to rising sea levels spurred on by climate change. As specially trained diver-archaeologists race to document its Paleolithic rock art before it’s too late, everyday people can now marvel at the wonders within, too, thanks to a permanent virtual exhibition in Marseille that opened this month.
Cosquer Méditerranée is an immersive, 3-D presentation that takes visitors through a realistic reproduction of the cave in an experience reminiscent of both a museum and a theme park—without the need for special dive equipment or training.
“Tours” start in a replica of Cosquer’s diving club, followed by an elevator ride down to the entrance of the replica cave. Visitors then board “exploratory vehicles” and set off on a guided tour of the more than 400 artworks found on the cave’s walls, complete with audio commentary. Thirty-five minutes later, they return to “dry land” and head into a theater to watch a documentary about Cosquer’s discovery.
Participants can then learn about the prehistoric humans and animals who likely lived in or visited the cave during an era of much lower sea levels. Researchers believe that humans visited the cave during two distinct periods: 27,000 and 19,000 years ago. They created works of art depicting 200 animals from 11 species—including penguins, horses, and bison. The drawings include human figures, sexual symbols, shapes and signs, and handprints.
In fact, reports the Agence France-Presse (AFP)’s Pierre Rochiccioli, archaeologists believe the cave wasn’t near the water during the humans’ artistic heyday; instead, it was surrounded by grassland. When prehistoric humans first visited the site during the Paleolithic, or Old Stone Age, period, the water level was nearly 400 feet lower than it is today, according to the French government. In more recent times, the Mediterranean rose, submerging its entrance and shrouding the cave in mystery.
The building that houses the exhibition, called Villa Méditerranée and located on the Marseille waterfront, is an “architectural marvel” that served no real purpose until the regional Provence-Alpes-Côte d’Azur government decided to spend $24 million repurposing it in 2016, Renaud Muselier, president of the region, says in a statement.
“The underwater cave and its treasures provide an invaluable testimony, which is unique in the world, about the cave art of our distant ancestors,” Muselier says. “The replica of the cave will make the inaccessible accessible to all the region’s inhabitants, as well as visitors from France, Europe, and around the world.”
Though the cave is only accessible through its underwater entrance, its main chamber is mostly above sea level—for now. Water inside the real cave, whose entrance is submerged roughly 115 feet below the surface, has risen nearly five inches since 2011, and water levels continue to creep up millimeter by millimeter, reports the AFP.
Researchers are working quickly to digitize and map the cave and its artwork to both preserve it for posterity and create the virtual replica, which is accurate to within millimeters. Their hope is that more people can experience it—no matter what happens to the historic cavern.
As Bertrand Chazaly, a 3-D surveyor and diver leading the cave digitization work, tells the AFP: “We fantasized about bringing the cave to the surface.” Since that wasn’t possible, they’re doing the next best thing.