The underground Christian living during 1st century BC. This underground structure is construct…read morewith Roman technology. It is part of UNESCO world heritage site. I was surprised that there is window to above ground. I am guessing they use it for air ventilation.
The underground city has compartment that separated for each family. They did do a good tunnel with different wing. Structure is reinforced by brick. It is a bit wet and damping. Can imagine the living here without sunlight.