In 2000, two miners drilling an excavation tunnel below Chihuahua, Mexico discovered something truly astonishing. 

Within this cavern, exposed when the mining company pumped out groundwater, the miners found crystals measuring up to 12 meters (almost 40 feet) long and weighing up to 55 tons. They were 20 times bigger than the largest crystals anyone had seen before. It was one of the most spectacular mineralogical discoveries ever made. They named it the “Cueva de Los Cristales,” or the Cave of the Crystals.

Today scientists are working in the cave to conduct research on the crystals. While the conditions are extremely difficult—the temperature is 127 Fahrenheit and the humidity level is 90 percent—the efforts seem to be paying off. Researchers have discovered a new type of gypsum formation, collected ancient pollen in the crystals, and extracted the DNA of extremophiles trapped in the crystals to match them to their closest living relative.

The scientists are against the clock to document and study the cave before the mining company turns off the pumps and submerges the crystals once again.