ABSTRACT
Over a period of fifteen years (1997-2012), a microclimatic recording of the environmental conditions in Altamira Cave was carried out in four different stages by the research team from the National Museum of Natural Sciences (Spanish National Research Council, MNCN-CSIC). The extensive data compiled over the past 15 years do not recom-mend a cave reopening. The data showed that human activity inside the cave or in its sur-roundings (e.g., recent archaeological excavations) caused micro-environmental disturbances inside which would be detrimental to the conservation of rock art. The closure of the cave in 2002 was a clear benefit for rock art conservation. The presence of visitors inside could reactivate the deterioration mechanisms and would particularly affect the Polychrome Hall because is the most fragile area of the cave due to its special morphogeometric characteristics. In our opinion, the conservation of rock art should consider the maintenance or restoration of the natural conditions in a strictest possible way.
