During the following ages, it is known to be used by the Christians as a refuge against the Arab aggressors. Approximately, 15,000 people used to live in this underground city. We discovered only 8 floors until now. The city was sub-divided into separate sections for better defense purposes. Each section could be isolated from each other by closing the mill-stone shaped round rock gates with a diameter of 1.5m. The passages between these sections are about 30kms long. The corridors are very narrow. But the living rooms, meeting halls, churches and other facilities are very comfortable.
The storage rooms were capable of storing enough food for the residents for many months. The air shafts and water wells were adequate for 15,000 people, living all together for a very long time.