The prehistoric cave in Spain that is part of a World Heritage Site is the Cave of Altamira. It is famous for its Upper Paleolithic cave paintings featuring charcoal drawings and polychrome paintings of wild mammals and human hands.

The Cave of Altamira is located near the historic town of Santillana del Mar in Cantabria, Spain. It was declared a UNESCO World Heritage Site in 1985 for its outstanding prehistoric art. These paintings are considered some of the best-preserved examples of early human creativity.

Image Credit: Wikimedia Commons

For more detailed information, you can visit the UNESCO page on the Cave of Altamira.