Back in the 1960s, a little-known area of farmland in Southeastern Turkey yielded evidence of an ancient monument so old that many archaeologists couldn't believe the find.
Built at a time when human beings were not supposed to have had the skill or ability to do so, it rocked the archaeological community to the core.
Named after the hill it is found on, Gobekli Tepe is one of the world's most exciting yet strangest ancient sites.
Around a dozen other sites of similar age are also under excavation in the so-called “Stone Hills” area — an area extending for about 100 square kilometers around Gobekli Tepe.
The site is roughly six miles from the modern Turkish city of Urfa and is thought to date to the Pre-Pottery Neolithic age (roughly 9,500 BC and 8,000 BC).
If true, these dates would make Göbekli Tepe at least 11,000 years old.
The site consists of several large, circular structures surrounded by the world's oldest known megaliths.
It is debated what the site was used for, with most experts erring on the side of it having some ceremonial or religious significance.