Large male bison, best known figure in the Altamira cave in northern Spain |
The announcement was made by President of Cantabria Miguel Angel Revilla and Spanish Minister of Culture Angeles Gonzalez Sinde, who said everything would be done to "protect the complete conservation of the cave and its contents."
The Council of Scientific Investigations had drawn up a study to investigate the state of the paintings and to calculate the number of visitors that could be allowed in, "with all the requirements to preserve this exceptional site."
The cave, which lies about 30 km to the east of the city of Santander, was declared a world heritage site in 1985.
The 300-meter-long complex contains some of the best examples of stone age art with paintings of wild animals, such as horses, bison, wild boar and deer, in vivid colors.
The works date back at least 14,000 years and some could even go back as far as 30,000 years ago.
However, the paintings began to suffer damage as carbon dioxide levels rose due to increasing numbers of visitors. This led to the cave first being closed in 1977.
It reopened in 1982, but with visitor numbers severely limited. A replica cave was completed in 2001 and Altamira was finally closed in September 2002.