A cave in the Chihuahua desert in Mexico contains hundreds of huge crystals that can be 12 metres long and weigh 55 tonnes! It's called one of the deadliest places on Earth because of the hostile environment inside it.
The cave has temperatures of over 50 degrees Celcius and it's humidity is at 100%. Even with special equipment, no normal human could live longer than 20 minutes inside. The people who go down have to wear an isolating ice suit and a cool air blower in order to stay for a short period of time. Check out the source for more information and pics, they're amazing!
And with this, scientists have officially run out of things to research. Kidding aside, the study actually identified 120 different types of knots that happen inside your pockets.
What's worse, in over 3400 different trials, they found that the probability of a knot being formed in your pocket is incredibly high, and the knots will be formed within seconds! Check out the source for more info. There's a great deal of complex knott-math and scientific analysis that has gone into this.