But researchers just discovered something extremely unexpected under the heavily visited and heavily studied site: a hidden tomb that contained 12 completely intact human skeletons. Like the site itself, the tomb and skeletons likely date more than 2,000 years back to the ancient Nabataean civilization, which flourished between the fourth century BCE and first century CE. The tomb was found in August 2024 and recently announced by St. Andrews University in Scotland. The Petra discovery was made somewhat by accident using electromagnetic and ground-penetrating radar while scientists were studying the earth beneath the temple to plan for future flood mitigation projects.