After more than a decade closed to the outside world, Spain’s Altamira cave complex, which contains some of the most outstanding examples of Paleolithic art anywhere on the planet, is to reopen. Between now and August visitors will be chosen at random to be allowed into the caves, which are situated in the northern region of Cantabria, as part of an “experiment,” to see whether the site can be reopened to limited numbers, say Altamira’s board of directors.
The main chamber at Altamira, which was declared a Unesco World Heritage Site in 1985, features 21 bison painted in red and black, which appear to be to charging against a low, limestone ceiling. The paintings are estimated to be between 14,000 and 20,000 years old.
In 2002 the cave complex was completely shut off to most visitors after scientists detected green mold stains on the paintings in the main chamber. An exact replica of the caves and its paintings was created within a museum a few hundred feet from the original near the town of Santillana del Mar.
The Altamira board of directors says its goal is to provide limited public access to the cave, but without further damaging the paintings. “What we have done is to agree on an experiment, which is part of the conservation program,” says José Antonio Lasheras, the director of the Altamira National Museum and Research Center. “We have been evaluating the impact of researchers on the caves, and we thought that we could do this just as well using outside visitors,” says Lasheras.
The “experiment” will involve analyzing the impact that the presence of humans has on the paintings, examining air and rock temperature, humidity, microbiological contamination, leaks, and CO2 levels.
In 2010, researchers said that even the motion of visitors moving through the caves could prove disruptive, stirring the air and encouraging the release of mostly dormant bacterial and fungal spores. This could lead to the growth of new microorganisms, which for now seem to be slowing their advance.
From February of this year, five museum visitors a week will be chosen at random and offered a guided tour. “But anybody coming into the caves will have to wear the appropriate clothing and follow certain procedures,” says Lasheras. “They will be required to fill in a questionnaire afterwards, and will then take part in an anthropological survey.”
The organizers say they expect a total of 192 people to take part in the experiment. Visitors will also be invited to make suggestions on how the site should be managed in the future.
Since it was closed in 2002, only a handful of people have been allowed into the cave complex. In August 2010, Spain’s Ministry of Culture announced plans to reopen the site, pending a decision by a panel of experts about how many visitors would be allowed inside each year. But Spanish researchers warned that reopening could be the death knell for the ancient paintings.
Speaking at the time, Miguel Ángel Revilla, the then-head of the regional government of Cantabria, said he was opposed to the caves remaining closed: “Altamira is a valuable asset that we cannot afford to do without. Every famous person who comes here wants to visit it. The important thing is that somebody sees it.”
Lasheras says he accepts the idea of limited access: “Obviously, the best thing is for it to remain closed to the public. But the board has a duty, and that is to provide access to the site. We have a big responsibility, and sometimes we can be too cautious.”