Göbekli Tepe

As early as 1964, during an archeological survey, American researchers realized that this mound did not form naturally.

An excerpt from the article 18 facts about Göbekli Tepe
Traces of construction work were found on the top of the hill, thought to be the remains of a military post from Byzantine times. Pieces of broken limestone blocks lying nearby were considered to be elements of tombstones. The mound was believed to hide a Byzantine or Islamic cemetery.