A scientific project has successfully identified human DNA, at least 2000 years old, embedded in the walls of caves located in Spain and Portugal. Researchers discovered the genetic material adhered to cave surfaces, indicating a previously unknown capacity for caves to preserve human DNA over millennia. This finding challenges existing understandings of DNA degradation and preservation environments. The study demonstrates that cave walls can act as repositories of ancient genetic information, potentially offering new avenues for studying past human populations. Scientists believe the DNA originated from individuals who inhabited these caves centuries ago, leaving traces through contact with the rock. Further research aims to extract and analyze more DNA to learn about the lives and movements of these ancient people.