2000 years ago. Petra, Jordan... Petra - an ancient capital of the Nabatean Kingdom - is a city famous for its rock-cut architecture which was lost for centuries in sands and mountains. For many years Petra had been neglected and devastated before, in the 18-th century, it was reestablished for the mankind. Since that time there are a lot of tourists in Petra and it has been recognized as one of ...See More — with Naitik Kohli and Manh Pham.
Derinkuyu, Turkey. It's truly remarkable that people during its time were able to build such structures so reliably that they never collapsed and that the ventilation systems were so wonderful that they still work today. The air seemed refreshing cool the entire time we were underground. Up to 100,000 people could have lived here with their animals as well. There are storage areas and even burial sites inside the caves. Some of the levels have yet to be excavated.