Altamira Cave is 270 metres long and consists of a series of twisting passages and chambers. The main passage varies from two to six metres in height. Archaeological excavations in the cave floor found rich deposits of artefacts from the Upper Solutrean (ca 18 500 years ago) and Lower Magdalenean (between ca 16 500 and 14 000 years ago). Both periods belong to the Paleolithic or Old Stone Age. In the millennia between these two occupations, the cave was evidently inhabited only by wild...