<P> Altamira is located in the Franco - Cantabrian region and declared a World Heritage Site by UNESCO as the central element of the Cave of Altamira and Paleolithic Cave Art of Northern Spain . </P> <P> The cave is approximately 1000 meters long and consists of a series of twisting passages and chambers . The main passage varies from two to six meters in height . The cave was formed through collapses following early Karst phenomena in the calcareous rock of Mount Vispieres . </P> <P> Archaeological excavations in the cave floor found rich deposits of artifacts from the Upper Solutrean (c. 18,500 years ago) and Lower Magdalenian (between c. 16,590 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 animals . Human occupants of the site were well - positioned to take advantage of the rich wildlife that grazed in the valleys of the surrounding mountains as well as the marine life available in nearby coastal areas . Around 13,000 years ago a rockfall sealed the cave's entrance, preserving its contents until its eventual discovery, which occurred after a nearby tree fell and disturbed the fallen rocks . </P> <P> Human occupation was limited to the cave mouth, although paintings were created throughout the length of the cave . The artists used charcoal and ochre or haematite to create the images, often diluting these pigments to produce variations in intensity and creating an impression of chiaroscuro . They also exploited the natural contours of the cave walls to give their subjects a three - dimensional effect . The Polychrome Ceiling is the most impressive feature of the cave, depicting a herd of extinct steppe bison (Bison priscus) in different poses, two horses, a large doe, and possibly a wild boar . </P>

Who created the cave paintings of altamira spain