Rock detachments are at the very genesis of the morphology of the cave of Altamira, and of its gradual collapse. However, the collapse which occurred 13,000 years ago and which destroyed and covered its entrance, allowed the internal environment to maintain high climatic stability, very favourable for conserving the rock art.
During the 20th century, this balance changed due to the effect of the exchange of air with the outside and the consequent temperature fluctuations caused by the visits of hundreds of thousands of people. This was compounded by the construction of walls, roads and electrical installations to make visiting the site easier. The destabilisation of the microclimate put the cave in danger and brought about its closure in 1979. In 1982, following a research project, the cave was reopened with entry restricted to 8,500 people per year.
Between 1997 and 2001, preventive measures were adopted to control the potential risks caused by harmful use of the ground and environmental pollution. Land was purchased in the immediate surroundings of the cave, country paths and nearby livestock facilities were removed and the highway and access road to the Museum were diverted. This prevented contaminants from entering the cave due to the action of water filtration or from the atmosphere. For reasons of preventive conservation, the cave was closed to the public in 2002.
Between 2012 and 2014, the Research Programme for the Preventive Conservation and Access Regime for the Cave of Altamira was undertaken, promoted by the Secretary of State for Culture of the Ministry of Education, Culture and Sport (MECD, abbreviation in Spanish), as agreed by the Board of the Altamira Museum. The aim was to determine the impact of human presence on the conservation of the paintings, for the purpose of deciding whether its proper conservation is compatible with a regime of visits to the cave, and to draw up a preventive conservation plan.
In March 2015, the Board of the Altamira National Museum and Research Centre agreed a controlled and limited access regime which had been initiated in the context of the research programme. This is a strict access regime of 5 persons per week.
+ InformationSalto de línea Current regime of visits