The author returns to Turkey to explore Derinkuyu, an ancient underground city and survival bunker that could shelter thousands in times of crisis.
![rpvQetPP2F2vJ0cu3kFzGXcFUnz](https://suachuadieuhoa24h.com/wp-content/uploads/2024/06/rpvQetPP2F2vJ0cu3kFzGXcFUnz-60x90.jpg)
The author returns to Turkey to explore Derinkuyu, an ancient underground city and survival bunker that could shelter thousands in times of crisis.