Mexico’s Cave of Crystals

Silver miners first discovered Mexico’s Cave of Crystals almost a decade ago. This incredible underground cavern contains the world’s largest naturally grown crystals, where some structures reach almost 10 meters in length.

Breathing masks and cooling suits are essential as temperatures reach over 50 °C. Combine this with almost 100% humidity and every breath can lead to fluid condensing inside the lungs.

The new BBC series “How the Earth Made Us” accompanies Professor Iain Stewart, a geologist at the University of Plymouth, on a trip into the Naica silver mine.

Once the owners decide to end mining operations and pull out their pumps, The Cave of Crystals will flood and once again hide this spectacle from human eyes.