Deep beneath Cappadocia, Turkey, lies one of the most mysterious underground cities ever discovered—Derinkuyu. With 18 levels extending into the earth, this ancient refuge could shelter 20,000 people, complete with living spaces, chapels, storage rooms, and an advanced ventilation system. But the real question is: who built it, and why?

Some historians trace its origins to the Phrygians (800 BCE), the Hittites, or even an older, forgotten civilization. Others suggest it was designed as a sanctuary from invasions, cataclysmic events, or even something more mysterious. Could this have been one of the hiding places of the "black-haired people" mentioned in The Book of Enki? Some even speculate about connections to ancient extraterrestrial theories.

Regardless of its true purpose, Derinkuyu stands as a testament to human resilience and the secrets buried beneath our feet. What do you think—was it built for survival, defense, or something far beyond our understanding?