Cueva de los Cristales
The Shot: A team of speleologists negotiate massive beams of selenite crystal inside the Cave of Crystals in Chihuahua, Mexico, 2008.
The Photographer: Carsten Peter
The Full Story: Cueva de los Cristales was discovered in 2000 by a pair of brothers who’d been drilling in Naica, a lead and silver mine. It wasn’t a total surprise — the same geologic materials and processes that create the metals can also produce crystals. The question that’s puzzled scientists is how the ones inside this particular limestone cavern got so big. The main chamber has yielded some of the largest natural crystals ever found at 39 feet in length and 13 feet in diameter. The challenge has been getting in there to study them, or even photograph them. National Geographic photographer Carsten Peter wore a vest lined with ice packs, and another over it for insulation, beneath his full-body caving suit to survive the cave’s steam-room like interior, where temperatures hit 112 degrees F at 90 to 100-percent humidity. A respirator mask with ice-cooled air completed his getup. Even then, 20 minutes is the maximum time a person can spend inside the deadly Cave of Crystals.