I don't know Secertman. If this was a video made via computer CGI, or the real thing. Brillant piece of film if it was.i don't know if this is the right way to post it but check it out the link...
oh by the way i think it a AI art or something not real so i have a question...write back anybody.
I've heard of underground unknown cities before. The light derived would have had to come from some phosphorescent means on the roof of the caves. This would only to a slight measure describe where UFOs come from too, as there's some evidence of that also.
If these cave explorers were real, they either became diseased or were killed. Good find thanks.