Cauldrons in the Death Valley

[guohua]

I have heard of this before.
It is supposed to be a real event that was well documented and My Chinese Comrades in the MSS were very interested, enough so, that they did send a team in to locate and study, I don't remember or know the outcome.
Here is a short video I found.
 
Or this video is about 7 minutes long.
 To me, those look like severe radiation burns.
So,,,,,, does anyone know of these Cauldrons?
Have you any ideas?
Do you think they were placed on Earth as defensive devices to protect our planet?