Göbekli Tepe
Location: Turkey. Built: 10,000 B.C. It is believed that 6,000 years before Stonehenge was built, a remarkable stone temple was erected on a hilltop in southeastern Turkey by prehistoric people. Known as Göbekli Tepe, the site was previously dismissed by anthropologists, who believed it to be a medieval grave. In 2008, however, the German archaeologist Klaus Schmidt determined that Göbekli Tepe is, in fact, the oldest known temple in the world. The site was purposefully buried around 8,000 B.C. for unknown reasons, although this allowed the structures to be preserved for future discovery and study.