Officials of the famous Altamira cave in Cantabria have decided to extend an experimental program allowing a very limited number of visitors enter the site until February 2015.

Access to the cave with prehistoric wall art will remain restricted to just five people, plus a guide, once a week, while the lucky visitors are drawn from a lottery held among museum visitors.

From February of this year the original site has been receiving a highly restricted number of visitors, whose impact on the Upper Paleolithic cave art has been “minimal”, according to Gaël de Guichen, director of the research team.

In the cave there are paintings of 14,000 years old and has been closed for the public for years because experts feared that the moisture and fungi from the breath of visitors might damage the color of the paintings.

The cave, located near the town of Santillana del Mar, is a Unesco World Heritage Site.

Other tourists will continue to be able to visit an exact replica of the cave which was built in 2001 to preserve the original site from damage resulting from the presence of visitors.