To reach the only place in the world where cave paintings of prehistoric marine life have been found, archaeologists have to dive to the bottom of the Mediterranean off southern France.
Then they have to negotiate a 137-metre (yard) natural tunnel into the rock, passing through the mouth of the cave until they emerge into a huge cavern, much of it now submerged.
Three men died trying to discover this “underwater Lascaux” as rumours spread of a cave to match the one in southwestern France that completely changed the way we see our Stone Age ancestors.
Lascaux — which Picasso visited in 1940 — proved the urge to make art is as old as humanity itself.
Archaeologist Luc Vanrell’s life changed the second he surfaced inside the Cosquer cavern and saw its staggering images. Even now, 30 years on, he remembers the “aesthetic shock
But the cave and its treasures, some dating back more than 30,000 years, are in grave danger. Climate change and water and plastic pollution are threatening to wash away the art prehistoric men and women created over 15 millennia.
Since a sudden 12-centimetre (near-five-inch) rise in the sea level there in 2011, Vanrell and his colleagues have been in a race against time to record everything they can.
Every year the high water mark rises a few more millimetres eating away a little more of the ancient paintings and carvings.
Vanrell and the diver-archaeologists he leads have to work faster and faster to explore the last corners of the 2,500 square metre (27,000 square feet) grotto to preserve a trace of its neolithic wonders before they are lost.
An almost life-sized recreation of the Cosquer cavern will open this week a few kilometres (miles) away in Marseille.
AFP joined the dive team earlier this year as they raced to finish the digital mapping for a 3D reconstruction of the cave.
Around 600 signs, images and carvings — some of aquatic life never before seen in cave paintings — have been found on the walls of the immense cave 37 metres below the azure waters of the breathtaking Calanques inlets east of Marseille.
“We fantasised about bringing the cave to the surface,” said diver Bertrand Chazaly, who is in charge of the operation to digitalise the cave.
“When it is finished, our virtual Cosquer cavern — which is accurate to within millimetres — will be indispensable for researchers and archaeologists who will not be able to physically get inside.
The cave was some “10 kilometres from the coast” when it was in use, archaeologist Michel Olive told AFP. “At the time we were in the middle of an ice age and the sea was 135 metres lower” than it is today.
From the dive boat, Olive, who is in charge of studying the cave, draws with his finger a vast plain where the Mediterranean now is. “The entrance to the cave was on a little promontory facing south over grassland protected by cliffs. It was an extremely good place for prehistoric man,” he said.
The walls of the cave show the coastal plain was teeming with wildlife — horses, deer, bison, ibex, prehistoric auroch cows, saiga antelopes but also seals, penguins, fish and a cat and a bear.
The 229 figures depicted on the walls cover 13 different species.
But neolithic men and women also left a mark of themselves on the walls, with 69 red or black hand prints as well as three left by mistake, including by children.
And that does not count the hundreds of geometric signs and the eight sexual depictions of male and female body parts.
What also stands out about the cave is the length of time it was occupied, said Vanrell, “from 33,000 to 18,500 years ago”.
The sheer density of its graphics puts “Cosquer among the four biggest cave art sites in the world alongside Lascaux, Altamira in Spain and Chauvet,” which is also in southern France.