The Altamira Caves are a series of limestone caves located in northern Spain. They are famous for their prehistoric rock art, particularly the vivid paintings of bison that date back to the Upper Paleolithic period, around 36,000 years ago. These artworks provide valuable insights into the lives and environments of early humans. Discovered in 1868, the caves were designated a UNESCO World Heritage Site in 1985. The intricate designs and use of color demonstrate the artistic skills of our ancestors. Today, the caves are closed to the public to preserve the delicate artwork, but replicas and exhibitions allow visitors to appreciate this ancient heritage.