This is so amazing. I had no idea crystals could form into these huge columns. It honestly doesn't even look real, but it is. How absolutely amazing. I definitely have to see this one day. I hope I can. This is Cave of the Crystals or Giant Crystal Cave, located about 1,000 feet underground in Chihuahua, Mexico. The cave is extremely hot with temperatures reaching 136°F/58°C and the humidity is about 90 to 100%. Apparently, without the proper equipment to shield you, you can only last about 10 minutes in the cave. Whoo.