LASCAUX -- STILL UNDER THREAT!

This story is particularly interesting because I was able to gain entrance for my small group (7) into Lascaux in 1995. We did dip our shoes in acid (see below) but did not don hair nets and over-clothes. And we were only allowed in for 20 minutes with our excellent guide who spoke to us some 30 minutes before we went in.

Tucked away on a hillside in Montignac, in the Dordogne region of southwest France, the dame of Lascaux is an Ice Age treasure. Her walls are covered with remarkable pictures of horses, extinct bison and ibexes, painted when Man was still a hunter-gatherer and his survival far from certain. But the cave is also at threat from invisible invaders: microbial contaminants resulting from some awful mistakes made last century. Discovered by four teenagers in 1940, Lascaux became a massive draw after World War II, luring as many as 2,000 visitors a day. The cave was eventually closed to the public but the damage was done. Humans had brought in heat, humidity and microbes, upsetting the cave's ecosystem.

In 1960 as a young man, Jean Clottes was moved to tears by the confident strokes of black, red and ochre and their witness to the human odyssey. He later became a specialist in prehistoric wall painting -- and joined the campaign to save the precious site.

In an extremely rare visit to the cave last week, Clottes explained Lascaux had been affected in ways no-one could have predicted 60 or so years ago. "The cave was completely disturbed," said Clottes, 78. "In 1947 alone, they dug out 600 cubic metres of sediment to make an entrance and concrete path and installed lighting for the public." Six hundred cubic metres (22,000 cubic feet) is the equivalent to about eight 12-metre (40 foot) shipping containers.

The cave was closed in 1963 after green mould started to appear. This was followed in the late 1990s by the emergence of a white fungus, Fusarium solani. The bug either infiltrated the cave through a new ventilation system or during work during heavy rain to install it. The outbreak was tackled aggressively, including the use of fungicides and antibiotic compresses applied to the walls.

In 2007, black spots of a different fungus, of the Ochroconis group, sparked the UN's Educational, Scientific and Cultural Organisation (UNESCO) to threaten to place Lascaux on its "World Heritage in Danger" list.

Chastened, conservationists today focus on a multi-disciplinary approach, believing any single thrust has side effects in other fields. The cave is fitted with passive sensors to monitor air circulation, temperature and humidity but intervention is kept to a minimum. The fungus seems to be in retreat, for it is limited to a few grayish traces on the bare rock and on small areas of some paintings.

Under scientific guidance, the human presence is limited to a total of 800 hours per year, including maintenance and academic research. Two hundred meters (yards) from the cave is a visitors' center with a replica that receives some 300,000 tourists a year.

Visitors to the cave don sterile white coveralls, a plastic hair cap, latex gloves and two pairs of slip-on shoe covers. Previously they had to dip footwear in a germ-killing bath, but this was deemed to be another source of destabilization.
Entrance is made through two airlocks, one of which is an "air curtain" designed to keep out external humidity yet not affect the natural drafts that circulate in the cave through fissures.

The paintings themselves, viewed in the glimmer of an LED forehead lamp, are breath-taking. The strokes by unknown hands trigger a shock of how we humans today are linked to our distant forebears. After exactly 45 minutes, our visit is over. We are ushered out, the doors are sealed and the bison, horses and ibexes return once more to dark and silence.

Recently Ian Tattersall, emeritus curator at the American Museum of Natural History in NYC who leads tours for the AMNH to the painted caves of France, was asked what was his greatest experience in the caves -- he answered quickly: "Lascaux."