The archaeological site preserved in the vestibule of the cave is structured in 8 archaeological levels (Carbon-14 cal BP dates):
At Altamira, the Magdalenian period is the best one dated, as Carbon-14 has been applied to some of the paintings made using vegetable carbon. The oldest figures have yet to be dated, as they were engraved or painted using red pigment. Dating them is more complicated as their composition lacks organic matter. Their age can be deduced using other criteria, such as stylistic criteria, by comparing them with objects of a known age, and also in relation to the human occupations of the cave.
Today it is also possible to apply a method based on the Uranium series, which had already been used for years in dating crusts and calcareous formations, and which in addition permits the size of the sample to be reduced to just a few milligrams. The results for the Altamira cave have been particularly interesting due to a symbol painted in red in the centre of the Polychrome Room, which dates back 35,600 years. This situates it in the Aurignacian, a period from which no remains have been found in the archaeological excavation of the cave.