What You Need to Know about The Lost Ancient (Deep-Underground) City of Derinkuyu

The mysterious lost ancient deep-underground city of Derinkuyu housed an astonishing 20,000 people, extending 18-levels down, and a staggering 280ft (85m) deep. The only thing more bizarre than this enigmatic marvel of engineering is that we do not know exactly who built it, how, why or even when...And this does not include the more than TWO HUNDRED additional underground cities that have been found in the area, including Kaymakli...