Perhaps they were hiding from the "sea peoples" that invaded and brought about the bronze age collapse. Currently reffered to as Palestinians. I noticed that whenever mainstream science can't explain an ancient monument or artifact, the go to explanation is "used for religious purposes". I don't suppose there is an altar at the end of the tunnel?

#grownostr  

 Not sure about that. There is no mention here about religious purposes. The tunnel is still a mystery and there is no conclusive evidence to confirm its purpose. It is left to conjecture or speculation it seems.