Marcel and three friends widened cave entrance days after discovery. They traversed 30-meter corridor to Axial Gallery. Walls covered in hundreds of prehistoric animal images. Horses dominate the nearly 600 depictions. Paintings created 17-22 thousand years ago in Magdalenian culture. Animals overlap with distorted proportions prioritizing creation act. Used ochre, charcoal, manganese oxides. Cave shows no long-term habitation signs. Served only for short visits to make art. Theories claim sympathetic magic for hunting success. Or ritual sanctuary for community ceremonies. Teacher alerted experts after initial disbelief. Opened to tourists in 1948 drawing crowds. Human breath, heat, humidity caused green molds. Fungal spores worsened damage. Closed to public in 1963 for preservation. Replicas now provide public access.