Title text:
If you're thinking 'Wait, a giant crystal cave in Mexico? What's that?' then I'm SO excited for the image search you're about to do.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3266/
Video of the "oops" of Pantai Remis
https://en.wikipedia.org/wiki/Pantai_Remis_landslide
and Wikipedia article on Retsof including a section about the mine