iot was in 1985 that the diver Henri Cosquer discovered, along the coast from Marseille, what has been called an “underwater Lascaux” after the famous cave network in the Dordogne. After several failed attempts, he managed to follow a narrow tunnel, 120ft below the surface of the sea, for almost 400ft and emerged in a stunning decorated chamber. Subsequent visits revealed many images of the horses, ibexes and deer common in prehistoric cave art, but also unprecedented pictures of seals and what look very much like penguins, including one which seems to show two males competing for a watching female. This initially raised questions about authenticity, though carbon dating of the charcoal confirmed that the drawings were prehistoric. The birds were later identified not as penguins but great auks (known in French as grands pingouins), an extinct species that looks similar but is not in fact closely related.
The cave came to wider public attention when three divers drowned there in 1991. It was classified as a historic monument the following year and the French state has conducted ever more precise and detailed surveys using laser scanners and high-definition photography. Portable devices can now also carry out chemical analysis, for example of pigments, on the spot. But the Cosquer cave is the only known decorated cave with an entrance under the sea, and until now it has only been accessible to very experienced divers. Global warming means that it is eventually likely to be submerged and that its amazing rock art will only be preserved virtually. It is particularly to be welcomed, therefore, that a compellingly accurate replica has now opened to the public at a prime site in Marseille, where it is hoped it will attract about 500,000 visitors a year.
Geologist and prehistorian Jacques Collina-Girard, who lectures at Aix-Marseille University, said a number of things made the cave unique. It was the first grotto decorated with prehistoric paintings found in Provence, and “a sanctuary of its type demonstrated that a significant population lived in the area”. Even though rising sea levels mean that the cave was once about four miles inland, it was still “nearer the sea than other major sites” and the animals represented within it indicated that “people of that period maintained contact with the sea and the coastal areas”. It has therefore helped to dispel the common image of prehistoric people as essentially inland hunters.
The Cosquer cave takes us back to a time when Francia was as cold as today’s Iceland. It appears to have been visited, but not lived in, over an unparalleled period of 14,000 years – from 33,000 per 19,000 anni fa. And it contains more than 500 separate images – some engraved with flint tools, some painted with fingers or made with charcoal now identified as coming from Scots pine. Experts speculate about the similarities and differences in how particular animals are represented in cave art across wide geographical areas, and what they tell us about cultural groupings. They try to interpret enigmatic images such as one which seems to represent a seal-headed man pierced by a spear or harpoon. And what about the handprints, found in Cosquer and a few other places, where parts of some fingers are missing? Had these been deliberately cut off or lost to frostbite? Or were the prints just made by people who had folded over some of their fingers, to represent a silent form of signalling, perhaps used in hunting, or to convey some spiritual meaning, rather like the sign of the cross?
The port in Marseille, where the new replica is sited, has always had a somewhat colourful reputation, with its crooks, chancers and poissonières (fishwives) famous for greeting customers with fruity sales pitches. A neglected area was transformed when the city was European capital of culture in 2013, con il creation of the MuCEM (Musée des civilisations de l’Europe et de la Méditerranée), the Musée Regards de Provence, devoted to the art of the region, and a striking building called La Villa Méditerranée. The last of these is within an artificial sea basin and notable for a huge overhanging cantilever, giving it a shape like an inverted L – locals have nicknamed it the Stapler and the Cap. Owned by the Provence-Alpes-Côte d’Azur region, it had no obvious function and so forms a perfect home for the replica at Cosquer Méditerranée.
The contract was awarded to Kléber Rossillon, a company already responsible for a similar project at the Chauvet cave in the Ardèche, di 100 miles to the north-west. So how was it possible for the architects, designers and technicians to recreate every detail of an environment they lacked the diving skills to go and visit for themselves?
“The national institutions created the numerical data about the cave and gave us all the documents, all the 3D data,” says Cosquer Méditerranée’s director, Frédéric Prades. “We committed ourselves to setting up a scientific committee made up of eminent historians, geologists, etc [led by Collina-Girard]. They followed the whole working process. It’s a guarantee that the result is scientifically faithful to the original. Even when we created the connecting tunnels, we consulted the geologists and they said: if we had had to dig a tunnel in the rock [on the original site], it would have looked like that, with that kind of rock.”
A company called Perspective(S) processed the digital data, 344 laser scans and 360-degree high-definition images to create a 3D model of the cave. This meant that the engineers and designers could put on virtual reality helmets and feel they were wandering about in it.
A digital milling machine used the 3D modelling to sculpt polystyrene blocks as moulds for the resin panels on to which photographs were projected. Expert painters then painstakingly recreated the original images by hand. Other specialists were employed to make reproductions of the stalactites and stalagmites, and to reproduce the exact matt, transparent and sparkling surfaces found in the cave.
“The physical replica itself is not a tool for scientists,” Prades stresses. “But the virtual reality work which allowed us to create our replica grotto will also be used by scientists – who will be able to move around in the cave without having to go there.”
The other key challenge was fitting the original cave into the slightly smaller space available underground at the Villa Méditerranée and “winding” it around the essential metal support beams. In some cases, rising sea levels mean that there is now very little space in the real cave between the floor level and a ceiling on which there is a striking image or design. And it is entered in the middle of a sequence of spaces which branch out in both directions but end in culs-de-sac.
It was therefore decided to include stylised access tunnels and to twist the real space to accommodate an exploratory vehicle which takes visitors through a series of six rooms on a circuit shaped like a squashed figure of eight, without having to retrace its route. Ciò nonostante, the replica feels utterly authentic as you are taken on a 35-minute journey through every part of the cave a visiting diver could see without having to crawl. This includes all the paintings and black drawings and 95% of the engravings. The visit also features several films about how the replica was created, though Prades reports that they had “a long discussion about whether we should have such films, because it is important to keep the magic and forget you are not in a cave”.