A documentary to 'rediscover' the so called Sistine Chapel of Rock Art and to tell the story of the discovery of a cave and some paintings that astonished the world 138 years ago. Filming this documentary lead its director, José Luis López Linares, through many rock caves around the world, grasping information about the life of the Magdalenian man -who lived twenty thousand years ago- and about an art form, the paintings, that make Altamira "the Prado museum of prehistory".