Nearly 5,000 cave paintings were discovered in northeastern Mexico in 2006 . This year , archeologists revealed their initial findings . The ages of the paintings are still not known . `` Their importance is that based on them , we have been able to document the presence of pre-Hispanic groups in Burgos , where before it was believed there was nothing , when in reality it was inhabited by one or several cultures , '' she said . But they are believed to have been made by hunter - gathering groups .
Nearly 5,000 cave paintings were discovered in northeastern Mexico in 2006 . This year , archeologists revealed their initial findings . The ages of the paintings are still not known . But they are believed to have been made by hunter - gathering groups .