Two thousand years ago, ancient tourists flocked to a Greco-Roman temple in Hierapolis, modern-day Turkey, situated on top of a cave once purported to be the gateway to the underworld.
Archaeologists have recovered thousands of artifacts from a cave in Xinjiang (an autonomous region of northern China) including stone tools, bronze and iron artifacts and animal fossils. Some date as far back as the Paleolithic Age, making them roughly 45,000 years old, according to the Institute of Archaeology at the Chinese Academy of Social Sciences.
Archaeologists have discovered 400 mysterious stone structures that could be thousands of years old in a remote desert area in Saudi Arabia. The stone structures- which were found using Google Earth - have been dubbed the 'gates' because they appear to look like field gates from above.